Teacher: Given a scientific passage and an answer, generate a question for the given answer.
Teacher: Now, understand the problem? If you are still confused, see the following example:
Passage: A frameshift mutation is a deletion or insertion of one or more nucleotides that changes the reading frame of the base sequence. Deletions remove nucleotides, and insertions add nucleotides. Consider the following sequence of bases in RNA:. Answer: nucleotides.
Solution: A frameshift mutation is a deletion or insertion of one or more of what that changes the reading frame of the base sequence?
Reason: The science passage defines frame mutation and the main compoment here is nucleotides. Hence the generated question is apt.

Now, solve this instance: Passage: The electrode at which reduction occurs is called the cathode . The cathode gradually increases in mass because of the production of copper metal. The concentration of copper(II) ions in the half-cell solution decreases. The cathode is the positive electrode. Answer: cathode
Student:
What is the electrode at which reduction occurs called?