The sentence that demonstrate correct punctuation of a compound sentence is Susan learned Russian with ease but, I could never get past the basics of Russian grammar. That is option A.
<h3>What is Compound sentence?</h3>
A Compound sentence is defined as the sentence that is made up of two clauses which are independent clauses that are joined together by a conjunction such as for, and, nor, but, or, yet, so.
From the sentence given, the correct sentence with the right punctuation is "Susan learned Russian with ease but, I could never get past the basics of Russian grammar".
This is because the first independent clauses must end with a comma before the conjunction.
Learn more about clause here:
brainly.com/question/541212
#SPJ1