Which factor is responsible for the variation in genetic makeup within a specific breed of domesticated animals?

An out-cross is produced when animals

The Free Martin condition is found in:

Which of the following statements is incorrect?

Select the correct pair of $X$ and $Y$:

Column $X$	Column $Y$
$(1)$ Cross-breeding	$(P)$ Mating between superior male of one breed and superior female of another breed
$(2)$ Out-crossing	$(Q)$ Mating between animals within the same breed
$(3)$ Interspecific hybridization	$(R)$ Mating between male and female of two different species

$S$ - Statement: The best example of cross-breeding is Santa Gertrudis.
$R$ - Reason: Cross-breeding involves mating superior males of one breed with superior females of another breed.