Directions: Read each sentence to find out whether there is any grammatical or idiomatic error in it. In the following sentences, a part is highlighted in each sentence which is error-free, the error, if any, will be in any other part of the sentence. The letter of that part is the answer. If there is 'No error', the answer is (e). (Ignore errors of punctuation, if any). Scientists has discovered that environmental (A)/ **factors play a greater role**/ than genetic variants in determining (B)/ the height of children (C)/ in low- and middle-income countries (LMICs). (D)

### Concept & Grammar Rule Subject-Verb Agreement. A plural subject must take a plural verb. ### Step-by-Step Solution - The subject of the sentence is "Scientists," which is a plural noun. - The verb used in part (A) is "has discovered," which is singular. - To maintain correct subject-verb agreement, the plural verb "have" must be used instead of "has". - Therefore, the correct phrase should be "Scientists have discovered". ### Exam Strategy & Shortcut Always identify the main subject of the clause first and immediately check if the auxiliary verb agrees with it in number (singular vs. plural). ### Common Pitfall Students often skim past the first word and assume the verb is correct, especially when reading quickly. Always pause and verify at the subject-verb pair. ### Final Answer Therefore, the correct answer is **A**.