Please help! I would really appreciate it! Which graph best represents a constant function? (5 points)

Select one:
a. A graph shows a nonlinear curve that joins the ordered pairs 0, 0, and 3, 2, and 5, 5.
b. A graph shows a straight line that joins the ordered pairs 0, 2, and 5, 2.
c. A graph shows a straight line that joins the ordered pairs 2, 0, and 2, 5.
d. A graph shows a nonlinear curve that joins the ordered pairs 0, 5, and 1, 2, and 5, 0.