You do a test cross and get the following progeny. A and $B$ are dominant, a and $b$ are recessive. Are genes A and B linked? If so$,$ how many m$.$u$.$ separate them? A$.5$ m$.$u$.$ B$.10$ m$.$u$.$ C$.20$ m$.$u$.$ D$.30$ m$.$u$.$ E$.40$ m$.$u$.$ F$.$ Thev are not linked.