Identify part $Y$ in the given diagram of a shoot apex.

Select the odd one out from the following.

The $Korper-Kappe$ theory was proposed by:

According to the $Apical$ $Cell$ $Theory$, the shoot apex contains a single apical cell with three cutting faces. This theory applies to some higher algae, bryophytes, and pteridophytes, but not to gymnosperms and angiosperms. Who proposed this theory?

What is a promeristem? It is a meristem which produces:

Identify $A, B$ and $C$ in the given diagram of the shoot apical meristem.