Sara wanted to gather data about the cost of local gyms in her area. She plotted the data and determined that the average gym costs consist of a one-time registration fee and a monthly fee modeled by the equation y = 10x + 30.Identify and interpret the y-intercept in this model.a. The y-intercept is 30. This is the cost of registration.b. The y-intercept is 30. This is the cost per month.c. The y-intercept is 10. This is the cost of registration.d. The y-intercept is 10. This is the cost per month.