In the following sentence, a part of the sentence is underlined. Below are given alternatives to the underlined part, which may improve the sentence. Choose the correct alternative. In case no improvement is needed, choose the alternative that indicates 'No improvement.'
They probably begun believing that the child was lost for all eternity.
A. Probably began believing
B. Had probably begun to believe
C. Have probably beginning believing
The second sentence uses simple past tense verb 'was', suggesting that the first verb also must reflect this. The past participle form 'begun' is incorrect here.
A shows the simple past tense form 'began', which makes the sentence grammatically correct.
B uses the past perfect tense form 'had begun' and the to-infinitive form of the verb, viz, 'to believe'. This also improves the sentence.
C uses the progressive form of both verbs, which cannot make the sentence meaningful. So, C is incorrect.
Only A and B improve the sentence.
Therefore, the correct answer is option 4.