Final answer:
The degree of the polynomial is 6.
Step-by-step explanation:
The degree of a polynomial is determined by the highest power of the variable in the polynomial. In this case, the polynomial is f(x) = (x - 2)^6 (x + 3)^4 (x - 5)^6.
The highest power of the variable x in this polynomial is 6, so the degree of the polynomial is 6.
Therefore, the correct answer is a) 16, as none of the other options represents the correct degree of the polynomial.