Generative cell was destroyed by laser but a normal pollen tube was still formed because
Vegetative cell is not damaged
Contents of killed generative cell stimulate pollen growth
Laser beam stimulates growth of pollen tube
The region of emergence of pollen tube is not harmed
Pollen grain or microspore divides mitotically forming a larger tube or vegetative cell and a small generative cell. Since, vegetative cells give rise to pollen tube and generative cell divides to form two male gametes, thus if a generative cell is destroyed by laser, a normal pollen tube will still form through the vegetative cell which is undestroyed.Hence, the correct answer is option 1.