Final answer:
The most accurate description of the degree of f(x) is Quartic (4th degree) since it has 6 turning points.
Step-by-step explanation:
The polynomial f(x) with 6 turning points cannot be linear (1st degree) since it has multiple turning points and a linear function has at most 1 turning point (where the slope changes sign).
A quadratic function (2nd degree) has at most 2 turning points. Since f(x) has 6 turning points, it cannot be quadratic either.
A cubic function (3rd degree) has at most 3 turning points. Since f(x) has 6 turning points, it cannot be cubic either.
A quartic function (4th degree) has at most 4 turning points. Since f(x) has 6 turning points, the most accurate description of the degree of f(x) would be Quartic (4th degree).