Answer: Option (b) is the correct answer.
Step-by-step explanation:
A crate will be difficult to carry or pull when we take it through doorstop. Whereas ax and screw will not be of much use for carrying the crate.
Therefore, we can conclude that out of the given options ramp would be an alternative to lifting a crate with a pulley as it will help in easily moving the crate form one point to another.