I did this in 8th grade so I don't completely remember but I am almost sure it is A.
<u>Answer:</u> DNA and RNA
<u>Explanation:
</u>
1. When the riddle says "both have<em> no direct relationship</em>", it refers to that although DNA and RNA work hand in hand, <u>they have large differences that help them complement and function</u>.
2. When we talk about "a free efficient <em>expression binds them</em>" we refer to gene expression. It is the process that allows you to obtain proteins from genes, <u>whose final stage</u> is the synthesis of proteins, <u>which binds both</u> DNA and RNA.
The best answer for this question would be: None.
Because the parts of the stages in writing like
<span>
correcting errors in grammar
correcting punctuation errors
correcting spelling errors
are all part of proofreading the writing structure that you have. While,
revising the overall structure and flow of your writing, is the one of the last things to do before confirming the final composition.</span>