Which of the following statements is true regarding pollen-pistil int…

The correct answer is Option (1) → The term "pollen-pistil interaction" encompasses the events from pollen deposition on the stigma to pollen tube entry into the ovule.

After pollination, the pollen grain and the pistil interact. The pistil decides whether the pollen may germinate and grow a tube to the ovule.

Option (1) The term "pollen-pistil interaction" encompasses the events from pollen deposition on the stigma to pollen tube entry into the ovule. — Correct. This is the book’s own meaning of the term. Pollen germination and the growth of the pollen tube through the style are part of it.

Option (2) Pollen-pistil interaction is a dynamic process involving the recognition and promotion of pollen, but not its rejection. — Incorrect. Rejection is part of the process. The pistil rejects wrong-type pollen by stopping its germination on the stigma or the growth of its tube in the style. So the interaction is recognition followed by promotion or inhibition.

Option (3) The pistil lacks the ability to recognise pollen, regardless of whether it is the right or wrong type. — Incorrect. The pistil does have this ability. It can tell compatible pollen from incompatible pollen through a chemical “dialogue” between the pollen and the pistil.

Option (4) Pollination guarantees the promotion of post-pollination events leading to fertilisation. — Incorrect. Pollination only brings pollen to the stigma. It does not guarantee that the pollen is of the right type, because pollen of other species or self-pollen may also land there. Post-pollination events are promoted only for compatible pollen.

NCERT Extract:
Pollination – “… Pollen-pistil Interaction : Pollination does not guarantee the transfer of the right type of pollen (compatible pollen of the same species as the stigma). Often, pollen of the wrong type, either from other species or from the same plant (if it is self-incompatible), also land on the stigma. The pistil has the ability to recognise the pollen, whether it is of the right type (compatible) or of the wrong type (incompatible). If it is of the right type, the pistil accepts the pollen and promotes post-pollination events that leads to fertilisation. If the pollen is of the wrong type, the pistil rejects the pollen by preventing pollen germination on the stigma or the pollen tube growth in the style.”
Pollination – “… All these events–from pollen deposition on the stigma until pollen tubes enter the ovule–are together referred to as pollen-pistil interaction. As pointed out earlier, pollen-pistil interaction is a dynamic process involving pollen recognition followed by promotion or inhibition of the pollen.”