Which photosystem is inactive in the red drop phenomenon?

The Hill reaction occurs in:

The high energy of electrons is used during the synthesis of .........

Which products formed during the light reaction of photosynthesis are used to drive the dark reaction?

The first electron acceptor molecule from $P_{700}$ to $NADP^+$ is considered to be .........

In photosystem $II$, the reaction centre chlorophyll-a absorbs $A$ nm wavelength of red light, causing electrons to become excited and jump into an orbit farther from the atomic nucleus. These electrons are picked up by an $B$, which passes them to an electron transport system consisting of $C$. Pick the right choice for $A, B$ and $C$.