Pretty confident that it is A, judging by that the word composition is used as a combination or a ratio of 2 things. Also none of the other options make sense.
Hello
_________
The answer is A. Nitrous oxide.(laughing gas)
Hope this helps
With the ever improving technology medicine has been revolutionized to help in so many ways. There are now improvements to many things medicine can do like look for new pharmaceuticals, correct mistakes in surgeries, prolong life, and help provide in depth research into diseases and their anecdotes or cures.
