The correct option is D vegetative
When the anther matures and dehisces, each microspore in a tetrad separates. Each micropsore undergoes a mitotic division to produce two cells separated by a wall made of callose-
(1) A vegetative cell
(2) A generative cell
Vegetative cells are large in size and has an irregularly shaped nucleus. It has stored food reserve for the male gametes.
Generative cell is smaller, spindle shaped and has a dense cytoplasm with a regular nucleus