Will give out medals. Which sentence does not correct this run-on sentence?

The earliest form of the Internet was designed more than thirty years ago it was intended to be used by the military.

Question

Will give out medals. Which sentence does not correct this run-on sentence? 


The earliest form of the Internet was designed more than thirty years ago it was intended to be used by the military.

anonymous · Answer

A.
The earliest form of the Internet was designed more than thirty years ago, and it was intended to be used by the military.
 
 B.
The earliest form of the Internet was designed more than thirty years ago. It was intended to be used by the military.
 
 C.
The earliest form of the Internet was designed more than thirty years ago, it was intended to be used by the military.
 
 D.
The earliest form of the Internet was designed more than thirty years ago; it was intended to be used by the military.

anonymous · Answer

d

anonymous · Answer

If I'm wrong then please give me virtual slap.

anonymous · Answer

c   should separate the clauses with semicolon