...$A$... are structures present in the epidermis of leaves. They regulate process of transpiration and ...$B$... exchange. It is composed of two bean-shaped cells known as ...$C$... cells.

Choose the correct combination of $A , B$ and $C$ from the following options

• A

  $A-$ Stomata, $B-$ gaseous, $C-$ guard

• B

  $A-$ Stomata, $B-$ gaseous, $C-$ subsidiary

• C

  $A-$ Stomata, $B-$ water, $C-$ subsidiary

• D

  $A-$ Stomata, $B-$ water, $C-$ guard