can someone explain to me why C is correct

A customer has an individual cash account at Firm XYZ consisting of $200,00 of securities and $300,004 of cash. She also has a joint account at XYZ with her husband. which has securities with a market value of $375,000 and $125,000 in cash. If XYZ goes bankrupt, SIPC would protect: $500,000 in cash and securities for both accounts combined. B. $500,000 in cash and securities for each account. C. $450,000 in cash and securities for her individual account and $500,000 for the joint account. D. her individual account only, for the full $500,000