Which statement describes characteristics of a polynomial?

A polynomial is defined as a mathematical expression that consists of variables raised to non-negative integer exponents and their coefficients. The concept of the leading term is crucial in understanding polynomials, as it identifies the term with the highest degree, which plays a significant role in determining the behavior of the polynomial function.

Having a leading term with the highest degree is essential because it helps establish the polynomial's overall degree, which affects its graph and the end behavior of the function. The degree of a polynomial is defined by the highest exponent of the variable in the expression. Therefore, the statement regarding the leading term with the highest degree accurately describes a fundamental characteristic of a polynomial, confirming it as the correct choice.

Other options, while relevant to algebraic expressions, do not define polynomials correctly, as polynomials cannot have negative exponents or fractional exponents. Additionally, although some functions may be represented as root functions, that does not fit the definition of a polynomial. Thus, focusing on the leading term with the highest degree provides an accurate and clear definition of a polynomial's fundamental properties.