Blank (i) - C. repurposed: Physically, the nudibranch does extract (take out) the cells from the cnidarians it eats. It's a literal description of the biological event.

The sentence tells us that the nudibranch "incorporates" these cells "into its own tissue for defense."

- "Repurposed" means taking something belonging to one organism/system and using it for a new purpose in another.

- The phrase "into its own tissue for defense" explicitly provides the new purpose.

Blank (ii) - E. mechanism: The puzzle is how the cells survive digestion and reach the exterior. Mechanism names a biological process, which is exactly what the biologists cannot explain.


Blank (iii) - H. possess: The animal lacks the biological equipment to produce nematocysts this is a permanent structural absence. Develop is weaker and implies temporality; regulate mischaracterizes the absence as a control failure.