20. Jennie was saving money to buy herself a present on Christmas day. She started with Php 50 on the first week of
August, Php 70 on the second week, Php 90 on the third week, and so on up to the last week of November. Considering
that there are 4 weeks in a month, how much did she save from August to November?
A. Php 2 400
B. Php 2 800
C.Php 3200
D. Php 3 600​