Student or Learner
I was impressed by the way ..... she did it.
A. In which
This is the house .... I was born in.
In the first one the answer key shows IN WHICH. In the second one, it seems you and the answer key are on the same wavelength. I suppose :
This is the house in which I was born= This is the house which I was born in = This is the house that I was born in.
So what's wrong with ...which..... in ?
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.