Even after killing the generative cell with a laser beam,the pollen grain of a flowering plant germinates and produces a normal pollen tube because:

• A
  Laser beam stimulates pollen germination and pollen tube growth
• B
  The laser beam does not damage the region from which pollen tube emerges
• C
  The contents of killed generative cell permit germination and pollen tube growth
• D
  The vegetative cell has not been damaged