Correct Answer:
B. It's raining outside; take an umbrella.
The sentence \"It\'s raining outside; take an umbrella.\" is correctly punctuated. The contraction \"It\'s\" means \"It is\", while the semicolon (;) correctly joins two closely related independent clauses.
- It\'s = Correct contraction of It is.
- Its = Possessive form, not correct here.
- Semicolon (;) = Correctly joins two independent clauses.
- Comma (,) alone creates a comma splice in this sentence.
Therefore, the correct answer is: \"It\'s raining outside; take an umbrella.\"