Correct Answer: massive

Solution : The correct choice is the third option .

The sentence refers to the fact that trees have been dying in significant quantities or in great numbers within forests. The word massive here describes the extent or magnitude of the tree deaths, implying that a substantial number of trees have been perishing within the forest environment.

The meanings of the other words are as follows:

• Peculiar : This word means strange, unusual, or distinctive.
• Minority : This term refers to a smaller number or part, usually less than half of a total.
• Scanty : This word means insufficient, inadequate, or in short supply.

Therefore, the complete sentence would be: "Everyone who studies forests knows trees have been dying in large and massive numbers."