同温同压下，已知下列各反应为放热反应，下列各热化学方程式中反应热最小的是

A．2A (l) + B (l) =" 2C" (g)△H1	B．2A (g) + B (g) =" 2C" (g)△H2
C．2A (g) + B (g) =" 2C" (l)△H3	D．2A (l) + B (l) =" 2C" (l)△H4