Suppose a Simple Regression Model Is Calculated Assessing the Association

Suppose a simple regression model is calculated assessing the association between exercise (hours per week) and pulse per minute. Pulse is the dependent variable. The estimated slope is -0.5, r = -0.5 and r² = 0.25. Which of the following is true?

A) There is a perfect negative association.
B) 25% of the variation in pulse is explained by exercise.
C) As exercise increases by 1 hour, pulse increases by 0.5, on average.
D) There is a positive association between exercise and pulse.