In the above sketch of the stomatal apparatus, label parts 1,2,3, and 4 correctly. 

detailed solution

Correct option is B

Concept: Stomata are minute pores commonly present on the leaf epidermis. Every stoma is lined by two specific green epidermal cells called guard cells, which are large kidney-formed, or bean-shaped. Like some other ordinary cells, they additionally have rich cytoplasm and a nucleus. 

Chloroplasts are additionally present in them. Guard cells are additionally surrounded by particular epidermal cells called accessory cells.

Hence, the correct answer is option B.