The correct option is C Right down to the wire
An idiomatic expression has a meaning different from the meaning of the words in that expression. In the given sentence, "right down the wire" is not an idiomatic expression, the correct phrase is 'right down to the wire', which means 'until the last possible moment', it's based on the finishing line that's marked by a thread 'wire'. Hence option C is correct and A is incorrect. In option B, 'along the wire' literally means on the wire, like walking on the wire, it isn't the correct phrase as it has a literal meaning, hence option B is incorrect. 'Down to the right wire' is completely different from the idiom in option C, it has a literal meaning, considering there are many wires, and the 'right' wire has to be chosen.