Select the most appropriate option that can substitute the underlined segment in the given sentence. If there is no need to substitute it, select 'No substitution'.

There are many people in the world who believe that the earth is flat.

Here the correct answer is No Substitution.

Key Points

• The most appropriate option that can substitute the underlined segment in the given sentence is: No substitution.
• The original sentence, "There are many people in the world who believe that the earth is flat," is grammatically correct and conveys the intended meaning. Therefore, there is no need to make any substitutions.
• The use of "who believe" correctly indicates the present tense and aligns with the subject "many people" in the sentence.
• The original sentence is in the present tense and uses the verb form "believe" to match the plural subject "many people." This construction is grammatically correct and accurately expresses the idea that there are people who hold the belief that the earth is flat.
• Options 1 and 2 suggest changes to the verb "believe," but they do not improve the sentence or align with its intended meaning. Option 1, "who belief that," introduces an incorrect verb form, while option 2, "who should believe that," changes the meaning of the sentence by introducing a suggestion or obligation. Both options would result in a deviation from the original sentence's meaning and grammatical accuracy.
• Therefore, option 3, "No substitution," is the correct answer as it recognizes that the underlined segment in the original sentence does not require any changes to maintain grammatical correctness and convey the intended meaning.