Explanation:

- To find the number of parallelograms formed by intersecting parallel lines, use the formula: \((m-1)(n-1) = 60\), where \(m\) and \(n\) are the numbers of parallel lines.

- Solve for integers \(m\) and \(n\):

- \(m-1 \times n-1 = 60\)

- The factor pairs of 60 are: \((1, 60), (2, 30), (3, 20), (4, 15), (5, 12), (6, 10)\).

- Choose pairs for \((m-1)\) and \((n-1)\).

- \((m-1, n-1) = (5, 12)\) leads to \(m = 6\), \(n = 13\) or vice versa.

- \((m-1, n-1) = (6, 10)\) leads to \(m = 7\), \(n = 11\) or vice versa.

- Calculate \(m+n\).

- For (\(m-1, n-1) = (6, 10)\): \(m+n = 7+11 = 18\), but this is incorrect.

- Option: 4 — \(m+n = 13\) seems correct using \((m-1, n-1) = (5, 12)\) or vice versa.

- Option: 4 — 9

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