It is high time (1)/ that we leave (2)/ this place. (3)/No error (4)

Answer

2

Explanation

left will replace leave because - We use the following expression it.s time / it.s high time + Subject + Past Verb form to refer to the present moment
Look at the examples given below :
it is time we went home.
It is high time you went on diet.
Hence, that we left is the right usage