At what minimum temperature should hot tcs food be held

TCS food should be kept at 60+ degrees Celsius (140+F), assuming food is fully cooked and internal temperature has already attained the indicated values.  This is to prevent bacteria from multiplying, (only) some of which may be killed by the temperature.

answer; ///i believe that the correct answer is (a) specialized cells)

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."