It was anomalies
I am re posting this question since i did not get a response. The source of this question is Kaplan-
It was anomalies in the orbit of Uranus that led to the discovery of Neptune.
(A) It was anomalies in the orbit of Uranus that
(B) It was the orbit of Uranus showing anomalies that
(C) They were anomalies in the orbit of Uranus that
(D) The orbit of Uranus being anomalous was what
(E) The anomalies in the orbit of Uranus was what
My Ques: what is wrong with option E?
The problem with option E is that there is a subject verb disagreement. Anomalies was is incorrect. Anomalies were is the correct construction
Why is option A correct in that case? – In option A, the “it” is a placeholder pronoun and acts as the subject here.
It is X that led to Y is an accepted construction. Ask yourself “What led to the discovery of Neptune”. The answer is some fact led to it. The fact has to be referred to as singular.
Hope this helps!