Explanation:

- Option 1: 6 to 12 months

- Typically considered short-term credit.

- Not usually classified as long-term loans.

- Option 2: 2 to 5 years

- Falls within the medium-term category.

- Longer than short-term but not considered long-term.

- Option 3: 12 months to 5 years

- Overlaps both short-term and medium-term ranges.

- Some might classify the upper end as long-term, but generally seen as medium-term.

- Option 4: 5 to 20 years

- Fits the typical definition of a long-term loan.

- Longer durations allow for big projects or purchases with manageable payments.