Often cause the eye to become less responsive.
a. antihistamines

b. opiates

c. muscle relaxants

d. all of the above

muscle relaxants often cause the eye to become less responsive.

Explanation:

Many drugs hamper your vision. Stimulants like nicotine, cocaine, and Ritalin often cause overactive eye movement, resulting in inadequate attention to individual elements in the driver's field of view. Depressants like alcohol, heroin, and muscle relaxants often cause the eye to become less responsive.

its c because i have that test too