When Making a Transgenic Mouse by Microinjection of Foreign DNA

When making a transgenic mouse by microinjection of foreign DNA into fertilized eggs

A) there is random integration of the transgene into the embryonic genome.
B) there is disruption or mutation of a targeted gene in the embryonic genome.
C) the resulting mice are genetically identical to the donor nucleus.
D) the integration event into the embryonic genome usually occurs by homologousrecombination.