Step 1: Understanding the Concept
Genetic diversity is the variation in genes within a single species.
Step 2: Check the statements
Different alleles make individuals differ, true. Subspecies and races show this variation, true. It includes variation within a population, true.
Step 3: Find the false one
Diversity among different species is species diversity, so calling genetic diversity interspecific is incorrect.
Final Answer:
The incorrect statement is that genetic diversity is interspecific.
\[ \boxed{\text{(A) }\text{Genetic diversity is interspecific diversity}} \]