State the practical meaning of the slope and y-intercept for the situation described.The cost, in dollars, of cellular phone service with Econo-phone is given by C = 0.18x + 14.55, where x is the number of minutes used in one month.a.0.18 signifies the cost per minute, and 14.55 signifies the monthly service charge.c.14.55 signifies the cost per minute, and 0.18 signifies the monthly service charge.b.0.18 signifies the hourly phone rent, and 14.55 signifies the cost of the hardware.d.14.55 signifies the total phone bill, and 0.18 signifies the number of minutes used.