To export Account Based Forecast data, the user needs to add the fields that capture the forecasting quantity data, including any sales team adjustments. The 'Adjusted Forecast Quantity' field shows the forecast quantity after applying the adjustment percentage for each account product forecast. The 'Total Adjusted Forecasted Quantity' field shows the sum of the adjusted forecast quantity for all the account product forecasts in the same account forecast1. These fields are available in the standard report type of 'Account Forecasts with Product Period Forecast', so there is no need to create a custom report type. References: What Is Manufacturing Cloud?, Create Holistic Forecasts with Advanced Account Forecasting

You can use apex triggers to populate a custom metric on the forecast grid. A custom metric is a field that you can add to the Account Product Forecast (APF) or Account Product Period Forecast (APPF) objects to display additional information on the forecast grid. For example, you can create a custom metric to show the profit margin or the cost of goods sold for each product. To populate a custom metric, you need to write an apex trigger on the APF or APPF object that calculates the value of the custom metric based on the data in the record. You can use the standard or custom fields in the APF or APPF object as inputs for the calculation. For example, you can use the Planned Quantity, Planned Revenue, and Product Cost fields to calculate the profit margin. You can also use the fields from the related objects, such as the Account, Product, or Sales Agreement, by using the relationship queries. For example, you can use the Account Name or the Sales Agreement Status fields to filter the records for the calculation. After writing the apex trigger, you need to deploy it to your org and activate it. Then, you can add the custom metric field to the forecast grid layout and see the values populated on the grid. References: Create Custom Metrics for Account Forecasts, Apex Developer Guide, Relationship Queries

To create a custom metric for display on Agreement Terms, you need to create custom fields on the Sales Agreement Product and Sales Agreement Product Schedule objects, and map them using the Data.com Administration tool.
The custom fields must have the same data type as the default fields, and only number, currency, and formula field types are available for mapping.
Therefore, the correct answer is C.
Only number, currency, and formula field types are available for mapping.
Reference: Customize Salesforce Field Mappings, Create Custom Fields for Sales Agreement Products and Schedules

Explanation
The Mass Update function allows you to update multiple values of a single metric of a sales agreement in the Sales Agreement Terms tab. You can use this function to quickly adjust the planned quantity, revenue, or margin of multiple products and periods with a single action. The available actions are Decrease By, Increase By, and Replace With. These actions let you specify a percentage or an absolute value to decrease, increase, or replace the existing values. For example, you can use the Decrease By action to reduce the planned quantity of all products by 10% for the next quarter. You can also add a note to explain the reason for the mass update. References: Mass Update Sales Agreement Action, Update Multiple Values of Sales Agreements

According to the Salesforce Manufacturing Cloud documentation, to apply a rebate program to more than one account, you need to add each account to the members related list on the rebate program. This way, you can enroll multiple accounts as members of the same rebate program and track their transactions and payouts. You can add one account at a time, or use an existing Accounts list view to enroll multiple members. You can also enroll an account in multiple rebate programs if needed1. References: 1: Enroll Members to a Rebate Program