Darren's Father, Mother, and Sister All Have a Diabetes

Darren's father, mother, and sister all have a diabetes. Darren decides to seek the help of a health professional so he can avoid becoming diabetic as well. Who is the best person Darren should go to for nutrition advice?

A) the salesperson at the vitamin and supplement store
B) a public health nutritionist
C) a licensed dietitian nutritionist (LDN)
D) his trainer at the gym