Based on the DOE factorial plot provided, three correct statements can be identified: B, D, and E. Firstly, the highest tool age was achieved with metal hardness at a high level while keeping cutting speed at a low level, which corresponds to statement B. Secondly, the least tool age achieved when both cutting speed and cutting angle are at the low level, aligning with statement D. Lastly, all factors, as visualized in the plot, had 2 levels in the experiment (-1 and 1), which corresponds to statement E. Two factors being operated at 3 levels each and a 32 factorial design are incorrect because the graph indicates two levels for each factor.