Step 1: Understanding the Concept:
This question requires identifying the location (specifically, the type of tree) where Siddhartha Gautam attained enlightenment, as stated in the passage.
Step 2: Detailed Explanation:
The passage states: "...and finally sat down under a peepal tree, where he vowed to stay until enlightenment came."
The text clearly mentions that he sat under a peepal tree. This tree was later renamed the Bodhi Tree.
Step 3: Final Answer:
The correct option according to the passage is (C).