Question

which is true of mobile ladder locking mechanisms select the best answer: may be spring loaded may require manual activation must be properly engaged before use all of the above none of the above previous question next question

Explanation:

Mobile ladder locking mechanisms can have various designs. Spring - loaded mechanisms are a common type for easy operation. Some may need manual activation depending on the design. And for safety, they must be properly engaged before use. Since all the first three statements are correct characteristics of mobile ladder locking mechanisms.

Answer:

All of the above