Which prefix means toward, to, in the direction of?

• A. a-
• B. ab-
• C. ad-
• D. bi-

Answer: (C)

The directional concept being tested is how prefixes convey movement toward a target. The prefix that means toward, to, in the direction of is ad-. It signals approaching or adding to something, as in adduction, which describes moving a limb toward the midline of the body. The other options don’t fit this directional sense: a- often denotes without or a location in some terms, ab- means away from, and bi- means two. So ad- is the one that clearly communicates “toward.”