A). Ian is very excited about making homemade ginger ale; but he is also a little nervous.
Explanation:
According to the given run-on sentence, the best revision to give it so that it would become a grammatically proper sentence is to add the semi colon (;) after the first complete sentence.
Therefore, the correct answer is option A.
P. S: A run-on sentence is a type of sentence that occurs when two sentences are joined together without using a conjunction or proper punctuation.
