Researchers typically use randomized experiments to try and isolate a causal relationship between x and y (i.e., x causes y), what features of randomized experiments help to eliminate the three other potential reasons for observed correlation between x and y (listed below, provide a short answer for each).

a.y causes x (reverse causation)?

b. the correlation between x and y is caused by another variable (common cause)?

c. the correlation between x and y is random chance?