Which among the following products are produced by cyclic photophosphorylation ?

ATP only

The correct answer is Option (2)-ATP only

When only PS I is functional, the electron is circulated within the photosystem and the phosphorylation occurs due to cyclic flow of electrons . A possible location where this could be happening is in the stroma lamellae. While the membrane or lamellae of the grana have both PS I and PS II the stroma lamellae membranes lack PS II as well as NADP reductase enzyme. The excited electron does not pass on to NADP⁺ but is cycled back to the PS I complex through the electron transport chain .

The cyclic flow hence, results only in the synthesis of ATP, but not of NADPH + H⁺ . Cyclic photophosphorylation also occurs when only light of wavelengths beyond 680 nm are available for excitation. 

                                    (Cyclic photophosphorylation)