Read the excerpt from "bluesman on the move.” which word best describes the tone of these stanzas?

Based on the cause-and-effect relationship in this sentence, what is the meaning of the word illuminate? the colors and patterns on the stained glass windows were illuminated as thousands of candles burned during the special church service. a) to melt or change form b) to grow taller or wider c) to become extremely hot d) to light up or make clear