The subject of ethnobotany is _______.

A division of plant ecology
The study of botanical ethics
The use of plant extracts by different cultures
The application of botany to zoology
An unimportant branch of botany

The use of plant extracts by different cultures.

The subject of ethnobotany is the use of plant extracts by different cultures.

The subject of ethnobotany is the study of the relationship between plants and people, specifically focusing on how different cultures utilize and interact with plants. To determine the correct answer, we can rule out options that are clearly incorrect.

"The study of botanical ethics" is not a commonly recognized field, so we can eliminate this option. "The application of botany to zoology" is not directly related to the study of plants and people, so it can be eliminated as well.

Now we are left with three viable options:
1. A division of plant ecology
2. The use of plant extracts by different cultures
3. An unimportant branch of botany

To know which one is the correct answer, we need to understand the subject of ethnobotany. Ethnobotany examines how plants are used for medicinal, spiritual, dietary, and other purposes by different cultures around the world. It explores the traditional knowledge of indigenous peoples, historical uses of plants, and modern applications of botanical resources.

From this understanding, we can conclude that the correct answer is "The use of plant extracts by different cultures." This option accurately captures the essence of ethnobotany, as it focuses on the ways in which different cultures utilize and benefit from plants.