The correct option is B Protoplast fusion
Protoplasts fusion is a physical phenomenon during which two or more protoplasts come in contact and adhere with one another spontaneously or in presence of fusion inducing chemicals. Protoplast fusion is an important technique to make interspecific and intergeneric hybrids as protoplasts are isolated from plant tissues with the help of cell wall digesting enzymes and fused in-vitro. Since, only protoplasts and not whole plants are used, there are no incompatibility issues.