What is the main idea of this passage?

Câu hỏi: What is the main idea of this passage?

A. Searching for wrecks is much easier with new technologies like side-scan sonar.

B. Maritime archaeologists are concerned about the unregulated searching of wrecks.

C. The search of the RMS Republic failed to produce the hoped-for coins.

D. The popularity of treasure seeking has spurred a debate between preservationists and salvagers.