Why option C is correct please explain!

An auditor's independence is considered impaired if the auditor has: An immaterial, indirect financial interest in a client. An automobile loan from a client bank, collateralized by the automobile. A joint, closely-held business investment with the client that is material to the auditor's net worth. A mortgage loan, executed with a financial institution client on March 1,1990, that is material to the auditor's net worth. An auditor's independence is considered impaired if the auditor has: An immaterial, indirect financial interest in a client. An automobile loan from a client bank, collateralized by the automobile. A joint, closely-held business investment with the client that is material to the auditor's net worth. A mortgage loan, executed with a financial institution client on March 1,1990, that is material to the auditor's net worth