Respuesta :
B. $400 would be the answer when using front end estimation.
$5.20 in front-end estimation: $5.00
21 in front-end estimation: 21
Multiply $5.20×21
$5.20×21= $100 a week.
$100 a week multiplied by 4 weeks $400.
$100×4= $400
I hope this help's!
-LizzyIsTheQueen