Wood is

Given below are two statements : One is labelled as Assertion $A$ and the other is labelled as Reason $R$:

Assertion $A$ : Late wood has fewer xylary elements with narrow vessels.

Reason $R$ : Cambium is less active in winters.

In the light of the above statements, choose the correct answer from the options given below :

Assertion: Cambium is a lateral meristem and cause growth in width.
Reason: Cambium is made up of fusiform and ray initials in stem.

Each of the following terms has some anatomical significance. What do these terms mean ? Explain with the help of line diagrams.

$(A)$ Plasmadesmoses / Plasmodesmata

$(B)$ Middle lamella

$(C)$ Secondary wall