64. Thomas has a sample of materials and needs to determine its age. He can determine its relative-age by comparing
the rock layer the sample came from to another rock layer. Why is it sometimes difficult to determine the age of materials
in this way?
A. The oldest layers of rock are too close to the Earth's liquid mantle.
B. The youngest layers of rocks do not contain enough materials to evaluate.
C. The sequence of rock layers can be disturbed by erosion and earthquakes.
D. The rock layers have too many different types of rocks to determine their age.