Which event has a probability of one?

a. choosing a letter from the alphabet that is a vowel

b, choosing a number that is greater than one and is even

c. choosing a set of parallel lines on a polygon

d. choosing a square that is also a rectangle

Alex drew a circle with right triangle prq inscribed in it, as shown below: the figure shows a circle with points p, q, and r on it forming an inscribed triangle. side pq is a chord through the center and angle r is a right angle. arc qr measures 80 degrees.

If f(x)=x^3 and g(x)=2x+7 when g(x)=-5

D. in a discrete probability distribution, the sum of the probabilities for the discrete variables will be > 1. true or false