Gene therapy is a form of . a) selective breeding b) artificial selection c) cloning d) genetic engineering

D) Genetic Engineering

Explanation:

Gene therapy is a type of genetic engineering because in gene therapy we have to manipulate the gene for our good.

There are three types of gene therapies:

1) Gene augmentation therapy

2) Gene knock out therapy

3) Gene silencing therapy

Gene augmentation therapy: In this type of gene therapy, the mutated gene which is non functional is retained in the genome and a functional copy of the gene is introduced into the genome.

Gene knock out therapy: In this approach the mutated/non-functional gene is replaced by a functional copy of the gene in the genome.

Gene silencing therapy: In this therapy, hyperactive genes like cancerous genes are silenced by introducing their miRNA gene in the genome.

the correct answer, according to e2020, is the second choice there is an occluded front in region a and a cold front in region b.