Here why not 1?

Here why not 1? 44. i 4 In which of the following aspect mutation br din is better than conventional breeding- (1 (2) (3) (4) Constraint by availability of desired genes. May produce new desired combination of trait. Use radiation. Less expansive.

Dear Student, In mutation breeding technique, chemicals or radiation are used in order to create mutant with the desirable trait. So, it is not constraint by availability of desired genes. But in conventional breeding, mutation is very slow and there is a very little chance of producing trait that breeders like to see. Thank You!