Vernalization is best defined as:
That points to B: Acceleration of flowering by prolonged cold exposure. Compared with the other options, Acceleration of flowering by prolonged cold exposure is the one that correctly describes the VERNALIZATION & FLOWERING concept. The wrong ones are A) Promotion of flowering by long days; C) Inhibition of flowering by cold; D) Induction of dormancy by cold. If you’re stuck, eliminate anything that contradicts a basic fact you already know for this topic.
Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.