Question

Choose the correct answer from the alternatives given.
Which of the following is a strong inhibitor of PS-II in photosynthesis

• A. Dichlorophenyl dimethyl urea
• B. Ethylene
• C. Indole acetic acid
• D. Chloroform

Answer 1

The correct option is A Dichlorophenyl dimethyl urea

DCMU (Dichlorophenyl dimethyl urea) is a herbicide which most effectively inhibits PSII in photosynthesis by the stopping CO${}_2$ fixation, which is essential for photosynthesis.

Thus, the correct answer is 'Dichlorophenyl dimethyl urea.'