Somatic cell gene transfer is used for P. transgenic animal production Q. transgenic diploid cell production R. classical breeding of farm animals S. in-vitro fertilization (A) P, R and S (B) P, Q and R (C) P and R (D) P only

Answer: (D) P only
Somatic cell gene transfer is primarily used for producing transgenic animals by introducing new genes into somatic cells. It is not typically used for classical breeding, in-vitro fertilization, or diploid cell production directly.