Correct answer is d. The Senate must ratify treaties with a 2/3 majority.
Explanation:
Only option D is correct, because according to Constitution senate is approving treaties signed by executive branch with at least two thirds of votes. The last rejected treaty was Convention on the Rights of Persons with Disabilities, which didn't had 2/3 majority, as 61 senators vote for and 38 against it.
The Romans built up their empire through conquest or annexation between the 3rd century BC and the 3rd century AD. At its height, the Roman Empire stretched from north-western Europe to the Near East and encompassed all the lands of the Mediterranean.