Ok, so lets convert all the percents into decimals to help us solve this problem
A 3.0%= 0.03
B 3.5%= 0.035
C 4.0%= 0.04
D 4.5%= 0.045
Now, we can multiply $200 by all the decimals we just converted to see which one will add up to $208
200*0.03= 6-------200+6=206 (this is not equal to 208 so it's not A)
200*0.035=7--------200+7= 207 (Still does not equal 208, so it's not B)
200*0.04= 8---------200+8=208 C is your answer