Which statement identifies the main idea in this excerpt from “Letter from Birmingham City Jail” by Martin Luther King, Jr.? You
warmly commended the Birmingham police force for keeping “order” and “preventing violence.” I’m sorry that I can’t join you in your praise for the police department. if you will observe them, as they did on two occasions, refuse to give us food because we wanted to sing our grace together. I am impelled to mention one other point in your statement that troubled me profoundly.
The subordinate clause here is A, "as the layers of ash slowly compressed". Subordinate means that it cannot exist on its own, it has to be a part of the main, independent clause.
