The horse and donkey, though closely related by sharing a common ancestor, are different species. They have different number of chromosomes hence pairing of homologous chromosomes during fusion of gametes becomes complicated. The mule will have an extra chromosome from the horse hence will have abnormalities such as sterility. A Mule is unable to reproduce due to this same phenomenon. Homologous chromosomes are not well paired for meiosis I.
"The idea has not yet achieved scientific consensus" is the one statement among the following choices given in the question that <span>best describes gene therapy. The correct option among all the options that are given in the question is the first option or option "A". I hope the answer has helped you.</span>
