Question

when a cnidarians nematocyst fires, what is injected into its prey?
water
paralyzing toxins
air bubbles
digestive enzymes

Explanation:

Cnidarians, like jellyfish, have nematocysts. These structures are used for capturing prey. When a nematocyst fires, it injects paralyzing toxins. This helps the cnidarian subdue its prey. Water is not injected as a hunting mechanism. Air bubbles are not relevant to this process. Digestive enzymes are used later in digestion, not at the moment of nematocyst firing.

Answer:

Paralyzing toxins