Epigenetic silencing of FLC involves:
That points to B: Histone methylation and chromatin remodeling. Compared with the other options, Histone methylation and chromatin remodeling is the one that correctly describes the VERNALIZATION & FLOWERING concept. The wrong ones are A) DNA mutation; C) Protein degradation; D) RNA splicing. 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.