Response:
B. The meanings of the prefixes chemo- and photo- point to the source of electrons.
Explanation:
The term chemo refers to chemical/drug, whereas photo relates to light. This can be demonstrated through the following examples:
Chemotherapy = treatment using chemicals
Phototherapy = treatment utilizing light
The resultant sequence would be: UAGCAU. U pairs with A, while C pairs with U. Hope this helps! Photon.