The answer is C.12:
Use ^ to denote an exponent..
f(x) = 3x^12 - 17x^8 + 11x^4 - 6x + 23..
We know from that fact that the number of zeroes (real or complex) in a polynomial is the same as the degree of the polynomial..
The degree is the greatest/highest power of the terms, which in this case is 12 (since 12 is the greatest exponent..)..
The degree is 12, thus it means there are 12 zeroes
