Terms can be combined if and only if they have the same variable and the same degree of exponents.
In our equation: 12a + 26b - 4b -16a, the similar terms are 12a and -16a, and 26b and -4b.
Combining or adding 12a and -16a will result to -4a.
Combining or adding 26b and -4b will result to 22b.
Therefore, the answer is -4a + 22b. (Option C)
