Answer:
If you need a ride home, Julian will be driving.
Step-by-step explanation:
The complex sentence comprises two clauses where one being dependent and the other being independent or both can exemplify independent clause and the punctuation marks vary according to the use of a conjunction. However, usually, there is a usage of a comma after the first clause except for some cases. The sentence that best suggests the use of punctuation marks as per this rule is the last option. The first one does not include a comma while the second one has the wrong usage of the comma. Thus, this makes us conclude the last one as the answer.