Answer:
The correct option is B. a single proton.
Explanation:
During intermediate stages of photosynthesis, water molecules are broken down releasing oxygen (O₂), hydrogen ions (H⁺) and electrons. Hydrogen ions and electrons are used in subsequent stages.
The produced hydrogen ions (H⁺) are composed by only a proton, without electrons. These positive ions are formed when a neutral hydrogen atom (H, with 1 proton and 1 electron) loses its single electron.
Therefore, the correct option is B. a single proton.
