Answer:
A. before sentence 1
Step-by-step explanation:
So, if we remove this misplaced sentence from the passage and reread it, we would see that we have no idea about what this passage is.
Sentence (1) provides more details on something ("they can be used...") but we don't know to what "they" refers.
Passage should start with intoducing the subject, giving us the name and function. The rest of the passage should be further elaboration and more detailed information on the subject.
With this in mind, we can safely say that this misplaced sentence belongs before sentence (1).