A switch that has two throws and switches only one wire is known as a (n) A. SPDT. B. SPST. C. TPDT. D. DPDT.

The correct answer is A. SPDT.

Explanation:

Let's recall that switches can be Single Pole (SP) or Double Pole (DP) depending on the number of electrical circuits controlled. In this case, it's just one and in consequence it's a SP.

Regarding the number of throws, ST switches close a circuit at only one position while DT switches close a circuit in the Up position, as well as the Down position (On-On). Our switch has two throws and it's DT.

The correct answer is A. SPDT.