At cellular level, the most dominant mode of transport for small molecules is:
That points to B: Diffusion. Compared with the other options, Diffusion is the one that correctly describes the BASICS of PLANT concept. The wrong ones are A) Active transport; C) Mass flow; D) Endocytosis. 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.