Which one of the following sentences contains two ideas joined by a connecting word?

AFrank went fishing on Saturday he caught many fish.
BMike ran after the bus.
CTina arrived at work earlier than usual.
DSally lives with her parents, although she could afford her own apartment.

Verified Answer :

Answer : D. Sally lives with her parents, although she could afford her own apartment. 

From the choices above, it can be deduced that the statement in letter D is the only sentence that contains two ideas being joined by a connecting word. The two ideas in the sentence in letter D are "Sally lives with her parents" and "She could afford her own apartment". These two ideas are connected by a conjunction "although" creating a compound sentence for that matter.

Sally lives with her parents, although she could afford her own apartment. -contains two ideas joined by a connecting word (although).