Antibodies produce proteins that attach to an invading virus. Antibodies attach to an invading virus as a target marker. Antibodies engulf the invading virus as a defense mechanism. Antibodies release enzymes that lyse the invading virus.
I gave my students this multiple choice question: Which immune system function is carried out by antibodies?

Only one answer is correct among these 4 choices:
- Antibodies produce proteins that attach to an invading virus.
- Antibodies attach to an invading virus as a target marker.
- Antibodies engulf the invading virus as a defense mechanism.
- Antibodies release enzymes that lyse the invading virus.

Could you tell me which one is correct?

Antibodies attach to an invading virus as a target marker.