The above p-v diagram represents the thermodynamic cycle of an engine, operating with an ideal monoatomic gas. The amount of heat, extracted from the source in a single cycle is
A. `p_(0)v_(0)`
B. `((13)/(2))p_(0)v_(0)`
C. `((11)/(2))p_(0)v_(0)`
D. `4p_(0)v_(0)`