Awater park conducted a study to investigate the relationship between outdoor temperature and the number of park visitors. the correlating linear model is shown, where x represents the number of degrees over 70°f, and y represents the number of park visitors.

y= 42 + 15x

what is the correct interpretation of the y-intercept?

a.
when the temperature is 70°f, the park can expect 0 visitors.
b.
when the temperature is 70°f, the park can expect 42 visitors.
c.
when the temperature is 70°f, the park can expect 57 visitors.
d.
when the temperature is 70°f, the park can expect 15 visitors.