which is true of mobile ladder locking mechanisms select the best answer: must be properly engaged before…

which is true of mobile ladder locking mechanisms select the best answer: must be properly engaged before use may be spring loaded may require manual activation all of the above none of the above previous question next question
Answer
Brief Explanations:
Mobile ladder locking mechanisms must be properly engaged before use for safety. They can be spring - loaded and may also require manual activation.
Answer:
D. All of the above