Answer:
Option B, The parents supplied different alleles
Explanation:
The genotype of any offspring is decided by the equal contribution of allele from both the parents. Hence, even when an organism is heterogyzous it is clear that the allele pair expressing the trait (due to the heterozygous pair) is formed by the contribution of both the parents equally which means one allele is given by one parent while other allele is given by other parent.
For instance -
For any heterozygous allele pair let’s say “Xx” , allele “X” would be donated by one parent while allele “x” would be donated by another parents.
Hence in order to form a heterozygous offspring the two parents need to contribute different alleles.
Therefore, option B is the correct answer
