Symmetric division in stomatal development occurs during formation of:
C fits best: Guard mother cell. Keep the PSS- Sec-F-Transport basics straight and Guard mother cell stands out as the precise answer. Avoid: A) Meristemoid; B) SLGC; D) Protodermal cell. 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.