What achievement of the roman empire survived its fall

This question is incomplete. I looked it up online, and this is what I found:

Select the correct answer.

Which sentence describes an achievement of the Roman Empire that survived its fall?

A.  Roman and Greek classics helped promote learning.

B.  Paper was created and used to keep a written history.

C.  The J.ulian calendar was used to keep track of time.

D.  The waterwheel was used to boost agriculture.

The sentence which describes an achievement of the Roman Empire that survived its fall is:

C. The J.ulian calendar was used to keep track of time.

Explanation:

The J.ulian calendar is the calendar we use nowadays. It was proposed by Julius Caesar in 46 BC, which is why it is referred to as "J.ulian". This calendar reformed the ancient Roman calendar. It is important to note that the calendar we use today is the result of several changes, some bigger than others. For instance, at a certain point, the calendar consisted of only 10 months. Later, when it already possessed the twelve months used now, some days were added to some of them, eventually adding up to the 365 days we are used to.

Note: The word "J.ulian" is typed this way because interprets it as a bad word or as a link, which prevents me from posting the answer.