Answer:
A woman called Karen, CCTV cameras
Step-by-step explanation:
The main idea was a woman feeling sorry for her son and sending the message. The other options were the result of her actions.
The main idea was that CCTV cameras recorded an unusual accident. The other options explained what they recorded.
The main idea was that A group of refugees from Myanmar tried to reach Indonesia, but weren't allowed to land. The other options explained what happened as a result.