The characteristic associated with the "tails" of the normal curve is ______

A) bell-shape
B) symmetry
C) probability
D) asymptotic

The tails of the normal curve are asymptotic, meaning they approach but never touch the x-axis. This is because the normal distribution extends infinitely in both directions, even if the probability of observing values far from the mean becomes vanishingly small. The other characteristics listed (bell-shape, symmetry, probability) apply to the entire normal curve, not just the tails.