Let X be a discrete random variable with the following cumulative distribution function:
Fₓ(x) = { 0, for x < 1; 1/₄, for 1 ≤ x < 2; 1/₂, for 2 ≤ x < 3; 1, for x ≥ 3 }
What is the range and probability mass function of X?
a. Range: [1, 3], PMF: Pₓ(x) = 1/₄
b. Range: [2, 3], PMF: Pₓ(x) = 1/₂
c. Range: [1, [infinity]), PMF: Pₓ(x) = 1/₂
d. Range: (-[infinity], [infinity]), PMF: Pₓ(x) = 0 for all x