Option:B is the correct answer.
B) $250, $300, $350, $400, $450
It was given that Brenda initially has: $ 200 in her account.
Also, at the end of the month she saves $ 50 each month.
This means that the she has next month is: $250
Then next month it is: $ 300
( since again she saves $ 50 the next month )
After that she will have: $ 350 in her account.
After that she will have: $ 400 in her account.
and at last she will have: $ 450 in her account with which she could buy her laptop.