You Are Studying Crickets and Notice That Individuals Have One

You are studying crickets and notice that individuals have one of two distinctive wing phenotypes (short-winged or long-winged) . From this, you can confidently conclude that

A) long- and short-winged crickets have different alleles at a locus controlling wing size.
B) only one genetic locus must contribute to the wing phenotype.
C) the trait must be polyphenic.
D) all of the above
E) none of the above