Limited access zones around masonry wall construction must meet all these requirements except:
a) equal to the height of the wall plus four feet
b) set up on the side of the wall that is scaffolded
c) run the entire length of the wall
d) restricted to workers actively engaged in building the wall

B) Set up on the side of the wall that is scaffolded

Explanation:

The limited access zones is made as some sort of precaution to the employees that work in a certain site that they are entering a potentially dangerous /hazardous area of the site.

It is true that putting a scaffold on  certain side of the wall could serve as a sign /pointer for a limited access zones. But it is not necessarily a requirement made by OSHA. It could also use some sort of yellow lines or wood blockades as pointer.