The correct answer is: A. 100% at the site.
A golden rule for the procurement of construction stones suggests that 100% of the stones should be inspected at the site before they are used. This is because it is important to ensure that the stones are of good quality and that they will be suitable for the construction project. If the stones are not inspected at the site, there is a risk that they may be of poor quality and that they may not be suitable for the project. This could lead to delays and additional costs.
Option B suggests that 67% of the stones should be inspected at the site and 33% should be under procurement. This is not a good option because it does not ensure that all of the stones are of good quality. There is a risk that some of the stones that are not inspected at the site may be of poor quality and that they may not be suitable for the project.
Option C suggests that 50% of the stones should be inspected at the site and 50% should be under procurement. This is not a good option because it does not ensure that all of the stones are of good quality. There is a risk that some of the stones that are not inspected at the site may be of poor quality and that they may not be suitable for the project.
Option D suggests that 33% of the stones should be inspected at the site and 67% should be under procurement. This is not a good option because it does not ensure that all of the stones are of good quality. There is a risk that some of the stones that are not inspected at the site may be of poor quality and that they may not be suitable for the project.