In the circuit shown in figure, reading of voltmeter is `V_1` when only `S_1` is closed, reading of voltmeter is `V_2` when only `S_2` is closed, and reading of voltmeter is `V_3` when both `S_1 and S_2` are closed. Then .
A. `V_(2)gtV_(1)gtV_(3)`
B. `V_(3)gtV_(2)gtV_(1)`
C. `V_(3)gtV_(1)gtV_(2)`
D. `V_(1)gtV_(2)gtV_(3)`