GMAT Sentence Correction (SC) | Re: The Atlantic Ocean, the second youngest of Earth's five oceans

An easy way to look at this.
A) The Atlantic Ocean has been expanding ever since - makes sense
B) The Atlantic Ocean expanding ever since - doesn't make any sense
C) The Atlantic Ocean is expanding ever since - doesn't make any sense
D) The Atlantic Ocean expanding ever since - doesn't make any sense
E) The Atlantic Ocean was expanding ever since - doesn't make any sense

Answer is A.

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