Einstein's mother's worry is not merely a family reaction but part of which narrative technique?

Correct answer: Ironic contrast

Option B is the strongest answer because the mother’s worry is placed against the later reality of Einstein’s extraordinary scientific greatness, creating an ironic contrast between an apparently troubling beginning and an exceptional outcome. The governing narrative idea is contrast in character development: an early judgement or fear is later challenged by events. Strictly speaking, the episode may also prepare readers to notice his unusual development, but the question asks for the technique that most directly describes the opposition between expectation and result. Option A, foreshadowing, would mainly suggest a future event in advance. Options C and D do not describe the function of the mother’s concern.