The artist has used a(n)
technique in this painting.

 The artist has mainly used a technique called blocking in This is where large areas of color are established at the beginning of a painting.

Explanation: There seem to be two other similar techniques being used together.

The other may be Blending where a lighter color of azure applied and slightly mixed with the blue. And Ala Prima where a new layer is applied before the previous layer has dries

true because it is true