In the office I never seem to have time until after 5:30 p.m

In the office I never seem to have time until after 5:30 p.m.,______many people have got home.A
In the office I never seem to have time until after 5:30 p.m.,______many people have got home.
A.whose time B.that C.by which
The baby is due in May,by ______the new house should be finished.
A.where B.which C.when
忘记说了，我要问的是为什么呢