Comprehensive and Detailed Explanation From Exact Extract:
Snowflake supports both implicit and explicit transactions. However, only specific statement types are allowed within transactions.
Option C:
This is correct. In Snowflake, transactions can be started with any of the following: BEGIN, BEGIN WORK, or START TRANSACTION. Transactions can be ended using COMMIT, COMMIT WORK, or ROLLBACK.
Official Extract:
"You can explicitly start a transaction using the BEGIN, BEGIN WORK, or START TRANSACTION statements and end it using the COMMIT, COMMIT WORK, or ROLLBACK statements." Source:Snowflake SQL Transactions Option E:
This is correct. Transactions should only include DML statements (INSERT, UPDATE, DELETE, MERGE) and queries. DDL statements (CREATE, ALTER, DROP) automatically commit and cannot be part of an explicit transaction block.
Official Extract:
"A transaction can contain only DML statements and queries. Any DDL statement implicitly commits the current transaction." Source:Snowflake SQL Transactions Option A:
Incorrect. DDL statements are not allowed inside explicit transactions. If used, they trigger an implicit commit.
Option B:
Incorrect. The autocommit setting cannot be modified within a stored procedure. Autocommit is session-level and not dynamically changeable within procedural logic.
Option D:
Incorrect. Snowflake does not support END TRANSACTION as a valid SQL command. The correct ending statement for a transaction is COMMIT or ROLLBACK.
References:
Snowflake Documentation: Transactions
COMMIT / ROLLBACK Commands
SnowPro Advanced Study Guide - SQL Semantics and Transaction Management

Role-Based Access Control (RBAC) is the Snowflake Access Control Framework that allows privileges to be granted by object owners to roles, and roles, in turn, can be assigned to users to restrict or allow actions to be performed on objects. A characteristic of RBAC as used in Snowflake is:
Privileges can be granted at the database level and can be inherited by all underlying objects. This means that a role that has a certain privilege on a database, such as CREATE SCHEMA or USAGE, can also perform the same action on any schema, table, view, or other object within that database, unless explicitly revoked. This simplifies the access control management and reduces the number of grants required.
A user can create managed access schemas to support future grants and ensure only schema owners can grant privileges to other roles. This means that a user can create a schema with the MANAGED ACCESS option, which changes the default behavior of object ownership and privilege granting within the schema. In a managed access schema, object owners lose the ability to grant privileges on their objects to other roles, and only the schema owner or a role with the MANAGE GRANTS privilege can do so. This enhances the security and governance of the schema and its objects.
The other options are not characteristics of RBAC as used in Snowflake:
A user can use a "super-user" access along with securityadmin to bypass authorization checks and access all databases, schemas, and underlying objects. This is not true, as there is no such thing as a "super-user" access in Snowflake. The securityadmin role is a predefined role that can manage users and roles, but it does not have any privileges on any database objects by default. To access any object, the securityadmin role must be explicitly granted the appropriate privilege by the object owner or another role with the grant option.
A user can create managed access schemas to support current and future grants and ensure only object owners can grant privileges to other roles. This is not true, as this contradicts the definition of a managed access schema. In a managed access schema, object owners cannot grant privileges on their objects to other roles, and only the schema owner or a role with the MANAGE GRANTS privilege can do so.
Reference:
Overview of Access Control
A Functional Approach For Snowflake's Role-Based Access Controls
Snowflake Role-Based Access Control simplified
Snowflake RBAC security prefers role inheritance to role composition
Overview of Snowflake Role Based Access Control

The error encountered during the cloning attempt arises because the schema STAGING as it existed on June
1st, 2021, is not within the Time Travel retention period. According to the schema history, STAGING was recreated on June 2nd, 2021, after being dropped on the same day. The requested timestamp of '2021-06-01
08:00:00' is prior to this recreation, hence not available. The STAGING schema from before June 2nd was dropped and exceeded the Time Travel period for retrieval by the time of the cloning attempt. Therefore, cloning STAGING as it looked on June 1st, 2021, cannot be achieved because the data from that time is no longer available within the allowed Time Travel window.References: Snowflake documentation on Time Travel and data cloning, which is covered under the SnowPro Advanced: Architect certification resources.