The photosynthetic electron transport that involves only photosystem I is called

Explanation

The correct answer is 'cyclic electron flow' because it involves only photosystem I and results exclusively in the production of ATP without generating NADPH. This process is crucial for adjusting the ATP/NADPH ratio to meet the demands of the Calvin cycle. In contrast, 'non-cyclic electron flow' and 'Z-scheme' involve both photosystems I and II, producing both ATP and NADPH. The option 'Non-cyclic electron flow or Z-scheme' is incorrect, as it describes pathways involving both photosystems, which does not align with the conditions stated in the question.