Which of the following statements concerning the standard normal curve is/are true (if any)?

a) The area under the standard normal curve to the left of -3 is zero.

b) The area under the standard normal curve between any two z-scores is greater than zero.

c) The area under the standard normal curve between two z-scores will be negative if both z-scores are negative.

d) The area under the standard normal curve to the left of any z-score is less than 1.

A. a, b
B. b, d
C. a, c
D. a