During photosynthesis what role is played by the radiant energy of the sun

The radiant energy of the sun is used by chlorophyll as an energy source to excite photosystems I and II, which are located in the membrane of the thylakoid.

Explanation:

When the light energy is converted into chemistry inside the photosystem, electrons are released and travel from photosystem II to photosystem I, through a protein complex; plastoquinone, cytochrome B, and plastocyanin.

When light hits, enzymes with REDOX power are activated while in photosystem I, one of the electrons converts NADP to NADPH, capturing protons from the stroma. Finally the NADPH and the ATP generated by the ATP synthetase of the thylakoid membrane, are products of the light stage of photosynthesis

The radiant energy of the sun is used to excite electron in photosystem.

During photosynthesis:

Hence, we can say that the the radiant energy of the sun is used to excite electron in photosystem.

To know more about photosystem, refer to the link:

link

the answer to your question is:

c. complementary base-pairing