Which mixture is more likely to produce a cool brown?

Correct answer: Blue and orange with more blue

A brown can be formed by combining complementary or near-complementary colours, and its visual temperature changes according to the dominant bias. Blue and orange with more blue can produce a brown carrying a cool, bluish influence, so option C is correct. Red-white, yellow-white, and violet-white mixtures are mainly light tints of their named colours, not the most suitable route to a cool brown. The blue should be added carefully to avoid an overly dark or dull result.