Hello there!
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(Complementary angles): These angles are not greater than or less than 90°.
Therefore, we then do
![\left[\begin{array}{ccc}12-90=78\end{array}\right]](https://img.qammunity.org/2019/formulas/mathematics/high-school/3b3n98ihczjc0bvw0x2i8y8o3dg8v3i57w.png)
.
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(Supplementary angles): These kind of angles would be angles that are no greater than to 180°.
We then do
![\left[\begin{array}{ccc}180-12=168\end{array}\right]](https://img.qammunity.org/2019/formulas/mathematics/high-school/s1m1bo25mavl7o9k3pgw8qodpu1dlet7vr.png)
.
Your correct answer:
(Option B).