A normal probability distribution

a. can be either continuous or discrete

b. is a continuous probability distribution

c. always has a standard deviation of 1

d. is a discrete probability distribution

Option B) is a continuous probability distribution

Step-by-step explanation:

Properties of a normal probability distribution:

The mean, mode and median of the data is same. It is a continuous probability distribution. The area under the curve is 1. The probability that any random variable X at a particular value is zero.

Thus, from the properties of normal distribution, the correct answer is:

Option B) is a continuous probability distribution