Answer: D. An experiment in which the outcome is repeatable
Step-by-step explanation:
An experiment is performed by utilizing a suitable methodology. The correctness of the methodology is analyzed by repeating a process several times so as to obtain concordant readings. Similarities in such readings with subsequent attempts will make the methodology as well as the outcomes of the results valid.
On the basis of the above explanation, D. An experiment in which the outcome is repeatable. is the correct option.