High K⁺ concentration inside root cells compared to medium indicates:
That points to C: Active transport. Compared with the other options, Active transport is the one that correctly describes the PSS- Sec-F-Transport concept. The wrong ones are A) Diffusion; B) Mass flow; D) Facilitated diffusion. 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.
