Example: Did you know that donating blood is actually good for your health? It is true! When you donate blood, your iron remains maintained at a healthy level. Reduction of iron in your body can lead to cancer, and no one wants that! Plus, donating blood reduces the risks of heart and/or liver ailments.
<span>B. nonrestrictive clause
Since it is nonrestrictive, it is not necessary and is set off by commas.
Hope this helps :)</span>
The answer is C, hope this helps