Pons, cerebellum and medulla together constitute:

In the following diagram showing axon terminal and synapse A, B, C, D and E respectively represent:

Consider the following diagram of the human eye with labelled parts $\mathrm{A},\mathrm{B},\mathrm{C},$ and $\mathrm{D}.$ Find out the incorrect match w.r.t. labelled part, its identification and feature/function.