SWLCAT Book 3-2 Practice Test

The correct response is based on the physiological effects that different levels of electrical current have on the human body. A current flow of 16 milliamperes falls within a range that primarily stimulates muscle contractions. At this level, the body's neuromuscular system reacts to the electrical stimulus by causing involuntary muscle contractions, which can be perceived as a strong tingling or "prickling" sensation.

This level of current is not sufficient to cause nerve paralysis, which typically occurs at much higher currents where nerve function is significantly disrupted. Additionally, while pain sensations can occur at this level, they are generally associated with stronger currents in the higher milliampere range or due to prolonged exposure. The loss of movement is also more closely linked with higher currents or prolonged exposure rather than the immediate response invoked by a current of 16 milliamperes. Thus, muscle contraction is the predominant reaction one can expect at this intensity of electrical current.