Answer:
(C) $745
Explanation:
The computation is given below:
For computing the bad debt  expense, first we have to determine the ending account receivable balance which is shown below:
Ending account receivable balance = Beginning account receivable + credit sales - collections - written off amount
= $20,000 + $70,000 - $74,700 - $400
= $15,300
So, the bad debt expense is
= Ending account receivable Ă— given percentage
= $15,300 Ă— 5%
= $745