Given a scientific question, generate a correct answer to it.

Example Input: What living things are considered photoautotrophs because they use sunlight and carbon from carbon dioxide to synthesize chemical energy in the form of carbohydrates?
Example Output: plants

Example Input: Which chemical element is the basis of all life on earth?
Example Output: carbon

Example Input: Which leukocytes are first to respond to bacterial infections?
Example Output:
neutrophils