3. two masons are preparing to work on a rolling scaffolding system. mason a says that since the scaffolding is greater than six ft high, it must have guardrails and toe boards. mason b says that the guardrails must be 42" from the walking surface of the scaffolding and be able to withstand 200 lb of impact. which mason is correct? a. only mason b is correct. b. only mason a is correct. c. both mason a and mason b are correct. d. neither mason a nor mason b is correct.