请选出下列正确的语调（）

A.His wife was cooking（降调）when we walked into the kitchen.（降调）
B.His wife was cooking（降调）when we walked into the kitchen.（升调）
C.His wife was cooking（升调）when we walked into the kitchen.（升调）
D.His wife was cooking（升调）when we walked into the kitchen.（降调）