One of the scientists in the video compared ice cores to rings on a
tree. When you look at a cross section of a tree trunk, you can see
rings in it. These rings indicate the annual growth cycle of the tree.
Counting them reveals how many years the tree was alive. What did
the scientist mean when he said that ice cores are like tree rings?

c. the initial amount of money placed in the savings account

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.