The correct answer is Option 1: anthers.

Explanation

Pollen grains are the microscopic structures that carry the male reproductive cells (gametes) of a plant. They are produced and housed within the anther, which is the pollen-producing sack sitting at the top of the male reproductive organ of the flower, known as the stamen.

When the pollen grains mature, the anther splits open (a process called dehiscing) to release them so they can be transferred to the female parts of a flower for fertilization.

Why the Other Options Are Incorrect

Option 2 (Locule): A locule is a chamber or cavity inside the ovary (the female reproductive organ) that holds the ovules. It does not contain pollen.

Option 3 (Ovules): Ovules are located inside the ovary of the flower. They contain the female egg cells and turn into seeds after successful fertilization.

Option 4 (Stigma): The stigma is the sticky, topmost part of the female reproductive organ (the pistil/carpel) designed to receive pollen grains during pollination. However, pollen grains are not found or produced there naturally; they are merely deposited there temporarily.