Final answer:
If the age of sexual maturation is a phenotypically plastic trait, there would be a relationship between genotypes and the age at which they reproduce. Environmental conditions, such as nutrition, can also affect the age of reproduction. Body size can also play a role in the age of reproduction.
Step-by-step explanation:
If the age of sexual maturation is a phenotypically plastic trait, we would expect to find a relationship between genotypes and the age at which they reproduce. Different genotypes would likely have different ages of reproduction. Additionally, environmental conditions, such as nutrition, can affect the age at which individuals begin reproducing. For example, individuals with better nutrition may reach sexual maturity at an earlier age compared to those with poorer nutrition. Body size can also affect the age at which different genotypes reproduce. Larger individuals may reach sexual maturity earlier than smaller individuals.
In conclusion, all of the options listed would be expected to have a relationship with the age at which individuals reproduce if the age of sexual maturation is a phenotypically plastic trait.