Final answer:
The coral snake is the type of snake among the given options that is not a pit viper. It does not have the heat-sensing pits characteristic of pit vipers and belongs to a different family known for its neurotoxic venom.
Step-by-step explanation:
The type of snake that is not a pit viper among the options provided is the coral snake (c). Pit vipers, such as rattlesnakes, copperheads, and cottonmouths, have heat-sensing pits between their eyes and nostrils which they use to detect warm-blooded prey. In contrast, coral snakes, which belong to the family Elapidae, lack these pits and are recognized for their bright coloration. Coral snakes possess neurotoxic venom that can be deadly, although they are generally less aggressive and less likely to bite than pit vipers. It's important to remember that coral snakes are not pit vipers, and their physical characteristics and behaviors differ significantly.