1mol理想气体从p1,V1,T1分别经：(1) 绝热可逆膨胀到p2,V2,T2；(2) 绝热恒外压下膨胀到p2′,V2′,T2′，若p2 = p2′ 则：( )

A、T2′>T2, V2′> V2, S2′>S2
B、T2′>T2, V2′< V2, S2′C、T2′= T2, V2′= V2, S2′= S2
D、T2′< T2, V2′