plz help me and WHO WANTS A MEDAL for the best response. Which sentence is the correctly written compound sentence?

A.
In the state of Arizona, the Colorado River carved the Grand Canyon, and it is 277 miles long.

B.
The Grand Canyon in Arizona is 277 miles long.

C.
The Grand Canyon was carved by the Colorado River in the state of Arizona; the steep-sided canyon is 277 miles long.

D.
The Grand Canyon was carved by the Colorado River in the state of Arizona, the steep-sided canyon is 277 miles long.

Question

plz help me and WHO WANTS A MEDAL  for the best response.    Which sentence is the correctly written compound sentence?
 
 A.
In the state of Arizona, the Colorado River carved the Grand Canyon, and it is 277 miles long.
 
 B.
The Grand Canyon in Arizona is 277 miles long.
 
 C.
The Grand Canyon was carved by the Colorado River in the state of Arizona; the steep-sided canyon is 277 miles long.
 
 D.
The Grand Canyon was carved by the Colorado River in the state of Arizona, the steep-sided canyon is 277 miles long.

7thgrader · Answer

THIS THE MATH SECTION PUT YOUR QUESTION IN THE ENGLISH SECTION

rainbow_rocks03 · Answer

I am on english

7thgrader · Answer

i know that i was freaking joking don't you remember me?

7thgrader · Answer

D. The Grand Canyon was carved by the Colorado River in the state of Arizona; the steep-sided canyon is 277 miles long.

Because it uses a semicolon properly - it consists of two sentences which can stand independently, but the full stop is replaced by the semicolon so now they are together :D

rainbow_rocks03 · Answer

yes i do.

7thgrader · Answer

Medal please if it helped ;)