Correct Answer: By means of rope ladders they scaled the wall.

Solution : The sentence with the appropriate use of the preposition is the first option.

Explanation: The preposition by is used to indicate the means or method by which an action is performed. In this context, by means of is the correct phrase to convey the idea that rope ladders were the method used to scale the wall. The first option correctly uses "by means of" to express the relationship between the action (scaling the wall) and the means (rope ladders).

So, the correct sentence would be: "By means of rope ladders, they scaled the wall."