EDTA and DTPA are examples of:
Chelators (C) is correct here. This is core MINERAL Transport: once you know the definition or pathway step, Chelators is the clear fit. The wrong ones are A) Enzymes; B) Phytohormones; D) Transport proteins. If the topic is about gradients or potentials, water/solutes move from higher to lower of the relevant quantity.
Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.