A wildlife biologist is interested in the relationship between the number of chirps per minute for crickets (y) and temperature. Based on the collected data, the least squares regression line is y = 24.5 + 16.1x, where x is the number of degrees Fahrenheit by which the temperature exceeds 50°. Which of the following best describes the meaning of the slope of the least squares regression line?

a) For every additional degree of temperature, chirps per minute increase by 16.1
b) For every additional degree of temperature, chirps per minute increase by 24.5
c) For every additional chirp per minute, temperature increases by 16.1 degrees
d) For every additional chirp per minute, temperature increases by 24.5 degrees