A fault (F) breaks three layers of sedimentary rock (S). An igneous intrusion (I1) has broken through the bottommost layer of rock. A second igneous intrusion (I2) has moved up the fault and pooled on top of the uppermost layer of rock. Which event would be considered the youngest?
A. Faults A and B are about the same age, and both are older than the five layers of rock.
B. Fault A is younger than fault B, and both are older than the five layers of rock.
C. Faults A and B are about the same age, and both are younger than the five layers of rock.
D. Fault A is younger than fault B, and both are younger than the five layers of rock.