Biology

The best example of a testable hypothesis in a biology experiment is: D."Plants will grow faster if exposed to blue light compared to red light."

This is a specific, testable hypothesis because it makes a clear prediction about the relationship between light color (blue vs. red) and plant growth. It is possible to design an experiment to test this hypothesis by measuring and comparing plant growth under different light conditions.

Here’s why the other options are not appropriate testable hypotheses:

A."The sky is blue.": This is a statement of fact about the color of the sky, which is due to scattering of light by the atmosphere. It’s not a testable hypothesis because it's a known observation, not a prediction that can be tested through experimentation.