Many Samoans enjoy a sport called kilikiti. This bat-and-ball game was derived from ______ blank kilikiti

Choice C is the best answer. The convention being tested is the coordination of main clauses within a sentence. This choice correctly uses a comma before the coordinating conjunction "but" to join the first main clause ("This bat-and-ball game was derived from cricket") and the second main clause ("kilikiti differs from cricket in a few key ways").

Choice A is incorrect. When coordinating two main clauses such as these, it’s not conventional to use a colon in this way after the coordinating conjunction. Choice B is incorrect. When coordinating two main clauses such as these, it’s not conventional to use a comma in this way after the coordinating conjunction. Choice D is incorrect. When coordinating two main clauses such as these, it’s not conventional to use a comma in this way after the coordinating conjunction.