Select the most appropriate option that can substitute the highlighted segment in the given sentence.
If they are going out, surely we will follow them.

Correct option is B

The correct substitution of the highlighted phrase is (b) go out.
Explanation:
This sentence is a conditional sentence using real condition (Type 1).
Type 1 conditionals are used to talk about real and possible situations in the present or future.
Grammatical Rule Used – Type 1 Conditional:
Structure:
If + Simple Present, will + base verb
· Correct form: If they go out , we will follow them.
· “go out” is simple present tense
· “will follow” is future simple
The original sentence incorrectly uses “are going out”, which is present continuous tense, creating a mismatch with the conditional format.
Corrected Sentence:
If they go out , surely we will follow them.
This keeps the conditional clause (if-clause) in simple present and the main clause in simple future, ensuring perfect tense consistency.