Which of the following pieces of personal information is a borrower asked to provide voluntarily on the loan application?

The correct choice is that a borrower is asked to provide race and sex voluntarily on the loan application. This information is linked to the Home Mortgage Disclosure Act (HMDA), which requires lenders to collect certain demographic information about loan applicants. However, this collection is designed to ensure that fair lending practices are upheld, and thus, applicants are not obligated to disclose this information—they can choose to provide it or to indicate that they prefer not to answer.

The reason why race and sex are included in this category is that these factors can help regulators monitor lending patterns and ensure that all consumers are treated fairly in the mortgage lending process. It's important to note that while this information is crucial for compliance and monitoring purposes, it is not mandatory for borrowers to disclose it, which is why it falls under voluntary information.

Other choices include sex, age, marital status, and variations thereof, but the correct answer specifically highlights the aspects related to voluntary disclosure for demographic tracking, which is a central focus of fair lending analysis.