Which of the following reasons correctly justifies that the polynomial 4x5+0x4−2x+1 has degree 5?
(a) 0x4 still contains the factor x4, so the highest power present is 4; therefore the polynomial is of degree 4.
(b) A polynomial’s degree equals the number of non-zero terms; here there are 3 non-zero terms, so the degree is 3.
(c) The term 4x5 has the highest power of x with a non-zero coefficient, so the degree is 5.
(d) Because a constant term increases the degree by one, adding 1 to the exponent 4 of the 0x4 term gives degree 5.