Pure water in open beaker has Ψp equal to:
Correct option is B, 0 MPa. In WATER POTENTIAL problems like this, the accurate statement is 0 MPa; the others are common mix-ups. Not these: A) 1 MPa; C) -1 MPa; D) Variable. Tissue transport questions usually turn on xylem vs phloem, living vs dead cells, or source vs sink.
Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.