Answer: Option 1) The new electric pencil sharpener does not sharpen well; I prefer the old manual one.
Explanation:
The two sentences that were combined are what we call independent clauses. An independent clause has a subject and a predicate. It expresses a complete thought on its own.
When combining independent clauses, we must be aware of the proper punctuation or conjunctions to be used to connect them. In this case, the best option is to add a semicolon since it is commonly used to join independent clauses.
A colon, on the other hand, does have an independent clause before it, but not necessarily another independent one after it. Even if it does introduce an independent clause, such clause usually explains or complements the first clause's meaning.
A comma is used to connect independent clauses when they are joined by a coordinating conjunction - and, but, for, so etc. -, which is not the case here.
