Select the most appropriate option to improve the underlined segment in the given sentence. If there is no need to improve it, select ‘No substitution required'.
When I left my house this morning, it was raining

Options

A. rained
B. is raining
C. rains
D. No substitution required

Answer

D

Explanation

The sentence starts in the past tense so it should end in past tense and the verbs should be consistent in the same tense. Hence, ‘it was(past form) raining’ is the most appropriate answer.