The yellow line lies along the contact between sandstone (on the left) and reddish mudstone (on the right). the red arrows point along a place where the sandstone continues into the mudstone. the four sides of the picture are labeled a, b, c and d. what is most likely correct about these rocks?

a) when the rocks were deposited, side a was the highest (it was on top).
b) when the rocks were deposited, side b was the highest (it was on top).
c) when the rocks were deposited, side c was the highest (it was on top).
d) when the rocks were deposited, side d was the highest (it was on top).
e) the rocks were formed from lava flows far down in the earth, and were not deposited.