Which statement best describes one rule for determining the relative age of a rock layer? question 12 options: a fault is always younger than the rock it cuts through an extrusion is always older than the rocks below it an index fossil is always younger than the rock layer it occurs in an intrusion is always older than the rock layers around it

Option A, a fault is always younger than the rock it cuts through

Reason:  

Basically there are three modes of determining the age of rock

1) In a sedimentary rock, the layer at the bottom is the oldest. It is called as law of super position

2) If a rock layers lies below an extrusion, then it is always older than the extrusion

3)a fault is always younger than the rock it cuts through

The correct answer is option A

The age of the rocks can be determined by the studying the faults that is always younger than the rocks it cuts through.

A fault is a crack or break caused in the rock. Any layer of the rock which is cut by the fault is older and the fault formed is younger.

There are many other ways which is used by the geologists to determine the age of the rock.

the correct answer is 2 and 4