Five layers of rock are cut by two faults. Both faults cut through all five layers of rock. Fault A breaks through to the surface, whereas fault B does not. Which of the following statements about faults A and B is most accurate?
a. Faults A and B are about the same age, and both are younger than the five layers of rock.
b. Fault A is younger than fault B, and both are younger than the five layers of rock.
c. Faults A and B are about the same age, and both are older than the five layers of rock.
d. Fault A is younger than fault B, and both are older than the five layers of rock.
b. Fault A is younger than fault B, and both are younger than the five layers of rock.