Help? The Middle East’s cold war, explained summary

In a speech to high school students, a business owner makes the following statement short response

Why do people live together and form societies

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