Lava is seen to have a "glittering"effect due to its natural composition: literally minerals. Depending on the rock that has been melted into this mixture, lava or magma can have varying effects applied to it's appearance, density, and the temperature it cools at.
The Answer to this problem would be...
A. Under-coverage.
Answer:
it presents an unanswered question
Explanation:
it's obvious because it says Then an adult voice said behind us: “What are you boys doing up here?” which is asking a question
