① Asexual reproduction refers to the reproductive mode that a new individual is directly produced by the mother without the combination of bisexual germ cells. Sexual reproduction refers to the reproductive mode in which germ cells combine to form a fertilized egg, and then the fertilized egg develops into a new individual, such as plants propagating through seeds.

(3) Asexual reproduction is a reproductive mode in which new individuals are produced by vegetative organs (roots, leaves and stems) of plants;

(4) Grafting refers to grafting the buds or branches of one plant to another plant, so that the combined two parts grow into a complete plant. In-stem propagation is a vegetative propagation of asexual propagation.

So choose: a