Option B: 'Grew' is a past tense verb and states an action that took place in the past. It is relevant to the given sentence that describes the past. Hence option B is correct.
Option A: 'Have' in 'have grew' expresses the present perfect tense. But 'have' and 'grew' do not function together. The syntax is: have + past participle 'grown', whereas 'grew' is a simple past tense verb (that is, it states a simple past tense action without the use of any helping verbs).Option C: 'Am growing' is in present continuous tense and states a continuous action in the present. But, the given sentence is set back in time.
Option D: 'Had grown' is in past perfect tense. It states an action that completed in the past, before another action took place. It does not relate to the situation presented in the given sentence.
Hence options A, C and D are wrong.