Which option shows a light tint of a warm colour?

Correct answer: Light pink

The governing concept is the difference between a tint and a colour family. A tint is made by adding white to a hue. Light pink can be understood as a tint of red, and red belongs to the warm colour group; therefore it is the correct choice. Dark blue and blue-green are generally cool, while dark violet is commonly treated as cool. The word “light” describes value, but it does not by itself change the original colour temperature.