The Boys End Up Being Adopted by Different Families

Multiple Choice

The boys end up being adopted by different families. Tom, the brother who lives in a large city, is diagnosed with attention deficit hyperactivity disorder (ADHD) . Tests were done and it was discovered that the level of ______________ in his blood was twice the levels found in the general population. The doctors are convinced this is the cause of his disorder.​

A) ​amino acids
B) ​glucose
C) ​mercury
D) ​neurotransmitters