Which part of the pistil serve as a landing platform to receives the pollen in a flower ?

Stigma

The correct answer is Option (3) - Stigma

The stigma is the part of the pistil that serves as a landing platform to receive pollen in a flower. It is a sticky, receptive surface located at the tip of the style. The pollen grain lands on the stigma and germinates, releasing a pollen tube that grows down the style and into the ovary. The pollen tube delivers the male gametes to the ovule, where fertilization can occur.

The style is the slender stalk that connects the stigma to the ovary. It is responsible for supporting the stigma and conducting the pollen tube down to the ovary.

The ovary is the swollen base of the pistil that contains the ovules. The ovules are the female reproductive structures of the flower. They contain the egg cells that are fertilized by the male gametes.

Therefore, the answer is stigma.