Since 2014, more than 230 earthquakes of magnitude 3 and above have occurred in a state, compared with an average of 1 year before 2008. Frequent earthquake activity has raised questions, and some researchers have found that since 2014, To avoid contaminating surface water with toxic wastewater generated during drilling and hydraulic fracturing during oil extraction, the state began to inject this wastewater between the impermeable layers of underground rocks. This behavior is likely to be the key cause of the earthquake. Which of the following, if true, would best support the above speculation? ['Pouring wastewater into rock water layers will reduce the friction between faults and make it easier to slide, thereby inducing earthquakes.', 'The state has explored more oil reserves since 2008, and oil extraction activity has increased significantly.', 'The state has fewer earthquakes but large magnitudes before 2008, and more earthquakes but small magnitudes since 2014.', 'Most continuous earthquakes are a series of aftershocks that occur after a strong earthquake, but this is not the case for the state earthquake.']