Concerning Making Animal Models of Human Disease, Which, If Any

Concerning making animal models of human disease, which, if any, of the following statements is false?

A) Pronuclear microinjection is a general way of making a transgenic animal and involves microinjection of foreign DNA into a fertilized egg cell.
B) Pronuclear microinjection is best suited to modelling recessively inherited single gene disorders.
C) Gene targeting using embryonic stem cells depends on having well-characterized embryonic stem cell lines that can readily allow transmission through the germ line.
D) Gene targeting using embryonic stem cells in mice is a popular way of modelling disease phenotypes that result from a gain-of-function.