Time required by two pipes A and B working separately to fill a tank is 36 seconds and 45 seconds respectively. Another pipe C can empty the tank in 30 seconds. Initially, A and Bare opened and after 7 seconds, C is also opened. In how much more time the tank would be completely filled?

A

34 seconds

B

39 seconds

C

33 seconds

D

37 seconds

E

32 seconds