This is all i know about caves: Caves are large, natural holes beneath the surface of the earth. Underground passages and caves are found in rocky landscapes across the world. They are found in areas with a lot of limestone, a common type of rock. They can be created in various ways, but most caves are hollowed out of rock by water.
The fact or state of being engrossed within something.
or
the process or action by which one thing that absorbs or it is absorbed by something else.
B
The other problems are not as easily solved; whereas, data collection over long periods of time is possible and was already done in the past, eg temperature and weather patterns. Therefore, this is the easiest limitation to overcome.