The correct option is D Micropropagation
A clone is a group of the organism produced from a single parent through asexual reproduction or progeny of single plant obtained by asexual reproduction while in other processes like hybridization, cross-pollination and self-pollination mixing of two gametes is taking place. Micropropagation is the process of multiplication of somatic cells artificially. During this process, the same type of cells ( morphologically and genetically) are formed. such group of cells are called as clones. Thus, the correct answer is option D.