Which of the following hypotheses is testable by using the scientific method? a) all man are mortal
b) the best color is blue
c) no life exists on other planets
d) all swans are white
e) swimming if fun

d

Explanation:

The only hypothesis that is testable using the scientific method would be that all swans are white.

The scientific method involves a series of steps through which scientists are able to arrive at a conclusion about the natural world. The steps include observation, drawing up falsifiable hypotheses from observations, testing the hypotheses using experiments, and then arriving at conclusions based on the data gathered from the experiment.

There is no way to test the mortality of all men as this will require harming humans in order to prove their mortality. The best color is also subjective as individuals have their preference when it comes to color. There is no way to prove the hypothesis that no life exists on other planets as this will require visiting other planets, a gesture that is practically impossible. That swimming is fun can also be subjective. Not everyone finds swimming interesting.

The hypothesis that all swans are white can be tested by sampling the population of swans in different areas and recording their colors objectively.

Hence, the correct option is d.