Which is the correct mixture for producing magenta in the light system?

Correct answer: Red and blue light

The additive RGB model uses red, green and blue as its primary lights. Red light combined with blue light is perceived as magenta, so option A is correct. Green plus blue produces cyan, and red plus green produces yellow. Option D mixes pigments, not light, and therefore belongs to a different subtractive colour context; it cannot answer a question specifically about the light system.