Scientists have developed a new herbicide for dandelions that is specifically designed to prevent the conversion of stored energy. Which process does this herbicide affect?

Ability to make ATP or the release of oxygen from chloroplasts.

Explanation:

Given that, ATP which is an acronym for Adenosine triphosphate,  is where the energy is stored and produced in a plant and at the same time Herbicides affect plants in the area of photosynthesis specifically affecting the release of oxygen from chloroplasts, which in turn prevents the generation of energy required for plant growth.

Hence, in this case, the new herbicides affect the ability to make ATP in plants or the release of oxygen from chloroplasts.