The correct answer is - False.
To trace the correlation between the rock layers by using fossils can be a big mistake, though occasionally it may provide the proper information, still it will be relying on luck.
The case is actually the other way around, the fossils can be correlated by using the rock layers, because each layer of rocks represents some time in the geologic past.
The fossils, on the other hand, are much more easy to be moved through the layers over time, because there can be disturbances, adjustments in the crust, or the rocks can change their composition under the influence of multiple factors. All of that can contribute to the fossils ending up at places where they aren't expected to be, so using them to correlate the rock layers will not be a very useful method.