Hey there!
Here is your answer:
The proper answer to this question is option A!
Reason:
You can tell which rock is older because how smooth it is, just remember this, if your comparing two rocks (to see which one is older) and its between a smooth rock, and a rough rock with a lot of edges, and points the smooth rock would be older, because of that you would know the rock went through hundreds (even thousands) of years of weathering with makes it a smooth, soft type of rock.
Therefore the answer is option A!
If you need anymore help feel free to ask me!
Hope this helps!
~Nonportrit