Select the most appropriate segment to substitute the underlined words in the given sentence.
Youth is the time when the seeds of character is sown.

The correct answer is the seeds of character are sown.

Explanation:
1. Subject-Verb Agreement: In the clause "when the seeds of character is sown", the subject phrase is "the seeds of character". The head noun of this subject is "seeds", which is plural. Therefore, it requires the plural auxiliary verb "are" rather than the singular verb "is".
2. Tense Consistency: The main clause ("Youth is the time...") uses the simple present tense to state a general truth. The relative clause following it should also be in the simple present tense in the passive voice ("are sown") to remain consistent.

Analysis of Options:
• the seeds of character will have been sowing: Incorrect because the active/continuous structure with future perfect tense is grammatically wrong for this context.
• the seeds of character had been sown: Incorrect because using the past perfect tense creates an unnecessary shift in tense.
• the seeds of character were sown: Incorrect because the simple past tense shifts away from the general truth established in the present tense.
• the seeds of character are sown: Correct because "are" agrees with the plural subject "seeds" and maintains the simple present tense.