The uplift pressure on a dam can be controlled by_________________?

The uplift pressure on a dam can be controlled by_________________?

1) constructing cutoff under upstream face
2) constructing drainage channels bet-ween the dam and its foundation
3) by pressure grouting in foundation

The corret answer is?
A. only (1)
B. both (1) and (2)
C. both (1) and (3)
D. (1), (2) and (3)