Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

Example Input: People stopped adding lead to gasoline because of environmental pollution.
Example Output: Why did people stop adding lead to gasoline?

Example Input: Protists are thought to be the oldest eukaryotes.
Example Output: What is thought to be the oldest eukaryotes?

Example Input: The specialized study of the motion of objects that are atomic/subatomic in size is called quantum mechanics.
Example Output:
The specialized study of the motion of objects that are atomic/subatomic in size is called what?