Answer:
A) 2(9x - 2)
Explanation:
The greatest common factor of 18x and -4 is 2.
B is wrong because 18 is not the greatest common factor of both, since 4 cannot be divided by 18 and result in a whole number.
C is wrong because 18x cannot be divided by 4 to produce a whole number.
D is wrong because it restates the problem in a different way, therefore not factoring it completely. 1 is a common factor of both, but not the greatest.