Chapter 4 - Polynomials - 4.3 Polynomials - 4.3 Exercise Set - Page 251: 1

The answer is $\color{red}{b) 5x^4 + 3x^3 - 4x + 7}$.

Remember that a term in a polynomial can be a constant, a variable or a variable with a coefficient. In this item, the description needs a polynomial with four terms, and among the choices, the one with four terms is $\color{red}{b) 5x^4 + 3x^3 - 4x + 7}$.