Answer:
The magenta and sky blue sentences are the answers.
Magenta) Admittedly, we cannot reuse or recycle all of the materials we use in our daily lives.
and
Sky Blue) My opponent would use these limitations of our ability to recycle to counter my points about the materials we can recycle.
Explanation:
Both these sentences are countering the speaker's claim
I think c or d the possibility of building a new school and the static’s that reveal problems
On the other hand is the transition phrase that introduces a comparison