When I ___ younger I ___ an idea of a wife who ___ with me in my thoughts as well as aims. ?

The sentence in question aims to convey a reflection on past perceptions and aspirations regarding a romantic partner during the speaker's youth. The correct choice is option B: "was / had / would be."

1. "When I was younger": The phrase indicates a specific time in the past. The verb "was" aligns with the past tense needed to express an action or state that occurred during “younger” years.

2. "I had an idea": The use of "had" here suggests possession of a thought or concept in the past, indicating that at that time, the speaker maintained a particular vision or understanding concerning a wife's role.

3. "who would be": The phrase "would be" expresses a hypothetical situation or expectation about the future in relation to that past idea. It suggests that the speaker reflects on their past visions and signifies what they hoped for in a partner, contingent on their thoughts and aspirations.

In contrast, other options fail to maintain consistent tense and meaning: "will be" and "is" suggest a present or future, which doesn’t align with the speaker's reflection on past thoughts. Therefore, option B effectively captures the intended meaning and temporal coherence of the sentence.