Select the most appropriate option to substitute the highlighted segment in the given sentence.
They are the people which are looking to expand their horizons in the fast-growing tourism industry.

Correct option is C

The correct substitution of the highlighted words is "who are looking to expand".

Explanation:

• The word "which" is incorrect because "which" is generally used for non-living things or animals (without names), whereas "who" is used to refer to people.
• The verb "are looking" correctly agrees with the plural subject "people".
• The correct relative pronoun for referring to people in defining relative clauses is "who", not "which" or "that" (though "that" is sometimes acceptable in informal use).
• "who is looking" (option b) is incorrect because "is" does not match the plural subject "people".
• "that are looked to expand" (option d) is grammatically incorrect as "looked to expand" is not in the correct active form.

Grammatical Rule Used:

Relative Pronouns Rule: "Who" is used for people, "which" is used for things, and "that" can be used for both but is less formal when referring to people.

Subject-Verb Agreement Rule: Plural subjects take plural verbs (People → are looking, not is looking).

Example Sentence:

Incorrect: She is the girl which won the award.

Correct: She is the girl who won the award.