Which molecules is the primary product of photosystem i?

NADPH

Explanation:

Photosystem is the complex structure formed by the chlorophyll molecule proteins and other light-harvesting pigments. There is two types of photosystem present in the plants: PSI and PSII.

The PSI system absorbs 700 nm wavelength of light and energises the electron coming from the PSII. This electron is then passed on to Ferredoxin to NADP reductase which converts the NADP to NADPH.

Since NADPH is formed after the electron is energized from PSI, therefore, NADPH is the correct answer.

reduced electron carrier NADPH.

The high-energy electron travels down a short second leg of the electron transport chain. At the end of the chain, the electron is passed to NADP^+  

+

start superscript, plus, end superscript (along with a second electron from the same pathway) to make NADPH.

that is wrong, its not thymus.