Question

John is conducting an experiment that involves melting ice cubes. Which of the following is most important for John to collect reliable data?

A.The outcome needs to be controlled.

B.An unbiased observer must witness the experiment.

C.Technology needs to be used to determine the results.

D.Only one variable should be tested during the experiment.

Answer 1

I think A not sure took this test 5 yrs ago

Step-by-step explanation: