Question

Fill in the blank with a suitable modal:
We _________ to stop pollution.

• A. Must
• B. Should
• C. Had better
• D. Ought

Answer 1

The correct option is D Ought

A verb is used to express an occurrence, action, or state. It is the grammatical centre of the predicate in a sentence.

An auxiliary verb is a verb which gives is used in the formation of tenses, moods, tones, etc.

Option D is correct as the sentence and infinitive indicates the use of a modal that indicates necessity.

The other options are wrong as we can not use them before to.

The correct answer is D) ought