Question

-where did you get to know her? -it was on the farm ___we worked. A,that B,where C,which D,where

Answer 1

B
It was on the farm that we worked还原为：we worked on the farm.它不是回答了问题
It was on the farm where we worked that I got to know her.还原为：I got to know her on the farm.这就回答了问题了

Answer 2

B做定语从句中的地点状语

Answer 3

D
你的理解对的,
work
on
the
fram所以应该用on
which，也就是where了，注意前面的on
the
farm是作was的表语，所以后面还要一个的，不能理解成前面是后面的宾语所以用which或that

Answer 4

此句有省略成分，还原为It
was
on
the
farm
where
he
worked
that
I
got
to
know
her.
强调部分省略，而where
he
worked作定语修饰farm.
谢谢采纳。