Ben placed four different solutions in beakers. He forgot to label the beakers. What should he do to ensure proper laboratory safety?
Start the experiment again...............
We have no details of what was in the beakers. And presumably, Ben has no means to differentiate them. The contents of the beakers should be safely discarded (another problem, of course, were the solutions aqueous?), and he should prepare his solutions again, and get it right this time by labelling the beakers appropriately.