The correct option is B pollen deposition on the stigma until pollen tube enters the ovule.
Pollen-pistil interaction is just not a momentary interaction between the pollen and the pistil.
This interaction is a continuous dialogue between pollen grain and the pistil.
It helps the pistil to recognize the pollen and check for compatibility.
Hence, pollen-pistil interaction includes all the events right from the pollen deposition on the stigma until the pollen tube enters the ovule.