Peaches are being sold for $2 per pound. if x represents the number of pounds of peaches bought and y represents the total cost of the peaches, which best describes the values of x and y?

a) the values of both x and y can be any real number.
b) the values of both x and y will be real numbers greater than or equal to 0.
c) the value of x can be any real number, but the value of y will always be a real number greater than or equal to 0.
d) the value of x can be any real number greater than or equal to 0, but the value of y must be an integer greater than or equal to 0.