It is acceptable for a lender to request a co-applicant in which of the following...

It is acceptable for a lender to request a co-applicant if the borrower will not qualify for the loan on their own based on their income, credit score, or other financial factors. A co-applicant, such as a spouse or family member, can help strengthen the application by adding additional income or improving the credit profile, which may help the borrower meet the lender's qualification requirements.

Other situations (B, C, D) such as future income, residency, or gifting funds do not necessarily require a co-applicant and are not acceptable reasons to mandate one.