You have created a custom module which must perform an action immediately after an order is placed, but only on the store front of the merchant site. You have selected the checkout_submit_all_after as the target event which the module will observe.
In which file will the event observer be declared?

The module MyCompany_MyModule will add a new page in the admin interface to display a custom entity in a grid.
You created a controller for this grid \MyCompany\MyModule\Controller\Adminhtml\CustomEntity\Index
Which two actions are required to make the new page accessible at the https://your.store.base.url/admin/my_module/custom_entity URL? (Choose two.)

Which method of a Magento resource model will remove a record from the database?

An Adobe Commerce developer is creating a module (Vendor_ModuleName) to be sold on the Marketplace.
The new module creates a database table using declarative schema and now the developer needs to make sure the table is removed when the module is disabled.
What must the developer do to accomplish this?

A merchant requires the ability to configure contact information for their brick and mortar stores as a CSV file upload. The module already exists and contains an etc/adminhtml/system.xml file where the new field can be added.
How do you specify the class that will process the uploaded file?