I think it's A. I'm not 100% sure.
The answer is B because it puts a coma in the correct spot to pause between the first half of the sentence and the second. The others either randomly placed a period, using the wrong word choices, or made it a run on sentence. :)
Answer:
1. Pockets: a small bag sewn into or on clothing so as to form part of it, used for carrying small articles.
2. Transistors: a semiconductor device with three connections, capable of amplification in addition to rectification.
3. Punch: strike with the fist.
4. Accurate: (of information, measurements, statistics, etc.) correct in all details; exact.
5. Led: cause (a person or animal) to go with one by holding them by the hand, a halter, a rope, etc. while moving forward.
Explanation:
