The dependent clause among the choices is option A. Although we had tickets to the game. The rest of the choices are independent clauses. A dependent clause consists of a subject and a verb but does not convey a complete thought and cannot stand on its own. It is usually introduced by a subordinating conjunction. The subordinating conjunction used in this dependent clause is the word "although".
A dependent clause, also called subordinate clause, is a group of words that at least has a subject and a verb, and that needs to rely on another clause in order to make sense because it can not stand by itself and have a complete meaning. Option A is the clause that best exemplifies it: if we look at it, it seems like something is missing, this is so because it needs an independent clause to depend on!. Here is an example of how dependent clauses should be used:
<u><em>Although we had tickets to the game</em></u><em>, we decided not to go.</em>
<em>"We decided not to go" is the independent clause (It can stand alone and have full meaning)</em>
