The first sentence, "Because of you, I was able to get the help I needed," is correctly punctuated.
The other options do not correctly use punctuation with the subordinating conjunction:
- "Because you offered to help." is a complete thought that doesn't require additional punctuation.
- "I got the help I needed; because I needed some help." is incorrect because a semicolon should not precede a subordinating conjunction like "because."
- "You came over: because I needed some help." is incorrect because a colon should not precede a subordinating conjunction.
So, the only correct option is the first sentence.