Answer:
b. Complementary gas masks
Explanation:
Adjacent means that the two angles are right next to each other and touching. The two angels in the photo are touching. Supplementary means that the two angels can for together to make a 180 degree line. The two angels in the photo make a 180 degree line. Complementary means that the two angels make a 90 degree angel. Since the two angels already make a 180 degree angels then, they cannot make a 90 degree angel. The question is asking for what it is not so, complements would be the answer.