Which of the following are public health measures that have fight disease?
a. regulating food supplies
b. monitoring water supplies
c. promoting vaccinations
d. all of the above

Hello there !
The correct answer is D. All of the above.
Hope this helps :)
(my main account is jojo12345679 :3)

The scientific method is a series of steps followed by scientific investigators to answer specific questions about the natural world. it involves making observations, formulating a hypothesis, and conducting scientific experiments.the steps of the scientific method are •observation-the first step of the scientific method involves making an observation about something that interests you•question-once you've made your observation, you must formulate a question about what you have observed. •hypothesis-once you've made your observation, you must formulate a question about what you have observed. •experiment-once you've developed a hypothesis, you must design and conduct an experiment that will test it.•results-the results are where you report what happened in the experiment. •conclusion-the final step of the scientific method is developing a conclusion.i hope that this you : )

The offspring will be blood type aa, bb, ab and oo or i