"is your pet on flea or heartworm prevention? " describes a question you would ask for the a. body system history b. body systems review c. environmental history d. medical history of the primary problem

a. body system history

Explanation:

A heartworm is roundworm which is parasitic in origin. It is thread like in appearance. It is spread from host to host through the bites of mosquitoes. It affects the lungs, arteries and heart.  

The body system history includes the information of the integumentary system, cardiovascular system, respiratory system, urinary system, gastrointestinal system, reproductive system, musculoskeletal system, head and neck and central nervous system.  

In heartworm is likely to affect the cardiovascular system of the pet hence, body system history should be reviewed.  

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).   so the answer is a.