Which mixture is more likely to produce a brighter orange?

Correct answer: Yellowish red and reddish yellow

The governing concept is pigment bias and minimising complementary contamination. To obtain a bright orange, choose a red and yellow that both lean toward orange: a yellowish red and a reddish yellow. Their mixture contains less unwanted blue or violet influence, so it retains greater saturation. Bluish red and greenish yellow introduce opposing biases, red and blue make violet, and yellow with violet tends to neutralise. Hence option B is correct.