16. When shellfish have cooked, their edges

A. crisp

B. curl.

C. burn.

D. soften.

When shell fish have cooked their edges curl.

Explanation: As per the Professional Chef page 535

Raw shrimp: it will turn pink and become firm

Live oysters, clams, and mussels: the shells will open when they are done

Shucked oysters, clams, and mussels: they will become plump and opaque. The edges of the oysters will start to curl

Scallops: they will turn white or opaque and become firm to the touch

Crab and lobster: the shells will turn bright red and the meat will become white or opaque.