Explanation:
In the given question, we need to determine which document requires the signature of the nominee during the nomination process. Let's examine each option to find the correct answer.

Account Opening Form:
The account opening form is a document that an individual fills out to open a bank account. It includes personal information such as name, address, contact details, and identification documents. However, the signature of the nominee is not required on the account opening form. This option is therefore incorrect.

Nomination Form:
A nomination form is a document used to nominate a person who will receive the benefits or assets in case of the nominator's death. It is commonly used in life insurance policies, employee provident funds, and other similar schemes. The nomination form requires the signature of the nominee to confirm their acceptance of the nomination. Therefore, the signature of the nominee is required on the nomination form. This option is incorrect.

Affidavit:
An affidavit is a sworn written statement made under oath or affirmation, typically used as evidence in a legal proceeding. It requires the signature of the person making the statement, but it does not involve the nominee. Therefore, the signature of the nominee is not required on an affidavit. This option is incorrect.

None of the Above:
Based on the explanations for the previous options, we can conclude that the correct answer is "None of the Above." None of the given documents, i.e., the account opening form, nomination form, or affidavit, require the signature of the nominee.

Therefore, the correct answer to the question is option 'D' - None of the above.