Given the word problem, we can deduce the following information:
1. Eric receives a net pay of $732.87 biweekly.
2. He has $172 withheld from his pay each pay period.
To determine the annual gross salary, we get the monthly gross salary first. Since the net pay is $732.87 biweekly and the withheld or the tax is $172, we add them and multiply by two to get the monthly gross salary. So,
Monthly gross salary = 2 ( $732.87+ $172) = $1,809.74
Then, we multiply $1,809.74 by 12 to get the annual gross salary.
Annual Gross Salary = 12 ($1,809.74) =$21,716.88
Therefore, the answer is d. $21,716.88.