Explanation:

- Initially, there is a 120 L mixture with a vinegar to water ratio of 7:5. This implies:

- Vinegar = (7/12) × 120 = 70 L

- Water = (5/12) × 120 = 50 L

- A certain amount of water is added, making the vinegar to water ratio 5:6:

- Vinegar remains 70 L.

- Let the new water quantity be W. Therefore, \(70/W = 5/6\).

- Solving gives W = 84 L.

- The new water quantity is 84 L. The percentage of new water relative to original water is:

- \((84/50) × 100 = 168%\).

- Correct answer: \(\large{\color{green}\checkmark}\) Option 5: 168%