Answer:
c.Alejandro’s nurturing parents. Alejandro’s genotype includes exceptional musical ability, but it’s his parents’ support of this ability that encouraged those genes to be expressed.
Step-by-step explanation:
this is an examole of the influence of environment on gene expression
His nurturing parent's support aided his skill developments for professionalism. Generally parents have great influence on the children social skill developments through thorough supervision and monitoring of their general activities.
In addition, they are the social vessels for their child's social interactions, and therefore determiners of the experience to pass though in their immediate environments. Conclusively parents influences determine a child future.
In Alejandro case, the profession of both parents, the monitoring of his activities with musical instruments, and his regular practice(for the development of neural pathways) showed influence of environment on the expression of genotype, which aided his professionalism.
If he was not born to family of guitarist,with no access to a guitar he may not be a professional despite his musical genotype. thus interaction between gene and parental nurturing (environments) favoured this.