If passive immunity lasts only as long as the gammaglobulins survive in body fluids, then passive immunity lasts only as long as what survives in body fluids?

Answer choices:
- Energy.
 - gammaglobulins
 - heat or cold
 - bacteria
 - Chemical energy
 - parasites
 - Leptospirosis
 - Veins and arteries.

 

  gammaglobulins        