Answer:
The powder is an unnatural substance.
Explanation:
The given extract is taken from the book "Silent Spring" written by Rachel Carson. This book is an environmental book which was first published on 27th September 1962. The book talks about the destruction caused by the uses of pesticides and insecticides to the wildlife, animals, birds and humans too.
The white granular powder is referring to the pesticide used in the agriculture. Since this white powder is harmful it is also unnatural substance.
So, the correct answer is the white powder is an unnatural substance.
