If a Sandstone Lies on Top of a Shale

Multiple Choice

If a sandstone lies on top of a shale,

A) the shale must be older,according to the principle of superposition.
B) the sandstone must be older,according to the principle of superposition.
C) the shale must be older,according to the principle of original horizontality.
D) their relative ages cannot be determined from the information given.