Given a scientific passage and an answer, generate a question for the given answer.

Let me give you an 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.
The answer to this example can be: A frameshift mutation is a deletion or insertion of one or more of what that changes the reading frame of the base sequence?
Here is why: The science passage defines frame mutation and the main compoment here is nucleotides. Hence the generated question is apt.

OK. solve this:
Passage: a) The water forms the bottom of the tube and thus where the node of the wave will be. Thus the air column is where the sound wave can exist. The larger the air column, the larger the wavelength. Frequency is inversely proportional to wavelength, thus the tube with the smallest air column will have the highest frequency. So the answer is tube C. Answer: wavelength
Answer:
In frequency, the larger the air column, the larger the what?