In absence of COP1 in nucleus, plants show:
B fits best: Photomorphogenesis. Keep the PSS-Sec-E-Sensory biology basics straight and Photomorphogenesis stands out as the precise answer. Avoid: A) Skotomorphogenesis; C) Delayed flowering; D) Dwarfism. Light and flowering items often hinge on which photoreceptor or day-length rule is in play.
Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.