What is known as a bi-product of cellular respiration, that is given off from the
Kreb's cycle.

Explanation:

In the presence of oxygen, under aerobic conditions, pyruvate enters the mitochondria to proceed into the Krebs cycle. The second stage of cellular respiration is the transfer of the energy in pyruvate, which is the energy initially in glucose, into two energy carriers, NADH and FADH2. A small amount of ATP is also made during this process. This process occurs in a continuous cycle, named after its discover, Hans Krebs. The Krebs cycle uses a 2-carbon molecule (acetyl-CoA) derived from pyruvate and produces carbon dioxide.

The Krebs cycle uses a 2 carbon moleculen(acetyl-CoA0 derived from pyruvate and produces carbon dioxide.

correct answer is a. and d.