How Can a Sill Be Distinguished from a Lava Flow

Multiple Choice

How can a sill be distinguished from a lava flow?

A) A sill is generally finer-grained than a lava flow.
B) Rocks above and below a sill will show evidence of heating,but only the rocks below a lava flow will show evidence of heating.
C) Sills generally have vesicles; lava flows generally do not have vesicles.
D) Sills generally overlie soils; lava flows do not generally overlie soils.