Sunken stomata are found in the leaves of

In a dorsiventral leaf,what is the position of the xylem and phloem?

In a dicot leaf:

In a leaf,the position of protoxylem is:

Select an incorrect statement.

Plant cells that are photosynthetically active are found in the $A$ layer of leaves and are $B$. Choose the correct combination of $A$ and $B$ from the below given options.