The correct answer would be A, Technician B is correct.
Using Aluminum ladder on a construction site is not a good choice at all. It conducts electricity and can give a power shock to someone if electricity gets conducted through it by any chance. Secondly, when it will be used on the construction site in open air under the sun, the aluminium ladder would get hot and workers wont be able to easily climb through it. Using wooden ladder would lessen the chances of any injury or casualty on the construction site due to electricity shock. So technician B is right who suggests that wooden ladder should be used instead of aluminium ladder.