Allan and Ellen have been married for years. In doing their personal income tax returns, they have always added all their medical expenses to claim on one tax return. A husband's net income is $40,000, while that of his wife is $42,000. His medical expenses amount to $5,500, while hers are $500. What is the highest federal medical expense tax credit they can claim? The non-refundable tax credit rate is 15%. Hint: - one spouse can claim the total eligible medical expenses paid - the 2022 Federal medical expense non-refundable tax credit formula: medical expenses in excess of the lesser of $2,479 for 2022 or 3% of net income Select one: a. $645 b. $636 c. $720 d. $570