An orange colour needs a lower value while retaining warmth. Which method is better?

Correct answer: Add a little dark red

The governing concept is changing value without destroying the colour temperature. A small amount of dark red deepens orange because red is already a warm neighbour of orange, so the mixture can become darker while remaining warm. Blue is cooler and complementary to orange, so much blue would neutralise the colour and reduce warmth. White raises value, and green also shifts orange toward a dull neutral. Thus option A gives the most suitable controlled correction.