Final answer:
The constant term in the polynomial 2x^3 - 8x^2 + 5x - 28 is -28.
Step-by-step explanation:
The constant term in a polynomial is the term that does not have a variable. In this case, the constant term in the polynomial 2x^3 - 8x^2 + 5x - 28 is -28, which means that the correct answer is option a) -28.