Which is the best example of the strength and advancement of the old kingdom’s central government?

A.) It constructed great monuments.

Explanation:

The old kingdom´s central government makes reference to the pharao´s age of the egyptian empire, so the best example of the strength that the old kingdom´s centrla government left, and can be visited and observed to this day are the great monuments that they built, among them the Giza Pyramids and other great structures.

c) troops march forward in close formation against newer, more accurate weapons

i would say the executive branch is because the executive branch is in charge of enforcing the laws and judicial branch is in charge of enforcing but the executive branch is most responsible for it all so i would have to say the executive branch.