A Round Wastepaper Basket with a 0

A round wastepaper basket with a 0.15-m radius opening is in a uniform electric field of 300 N/C, perpendicular to the opening. The total flux through the sides and bottom, in N . m²/C, is:

A) 0
B) 4.2
C) 21
D) 280
E) can't tell without knowing the areas of the sides and bottom