Select the option that will improve the highlighted part of the given sentence. In case no improvement is needed, select 'No improvement required'.
He was knowing her for a long time before he finally married her.

Correct option is C

The correct substitution of the highlighted words is (c) had known.
Explanation: “Know” is a stative verb and does not take continuous tenses like “was knowing” or “has been knowing.”
The sentence discusses two past events – (1) knowing her, and (2) marrying her – and the past perfect tense ("had known") is needed for the earlier action.
Grammatical rule used: When two past actions are mentioned, the earlier action should be in past perfect and the later one in simple past.
Example: I had finished my homework before the guests arrived.
�� Information Booster: Stative verbs like know, believe, love, hate, understand generally don’t take progressive tenses.
Why other options are incorrect:
· (a) has been knowing – incorrect as "know" can't be used in continuous tense.
· (b) No improvement – incorrect because "was knowing" is grammatically wrong.
· (d) had knew – incorrect past form. “Knew” is simple past; “had known” is correct past perfect.