Explanation:

Explanation:- In nature carbon can be obtained in various allotropic forms. Allotropes are those elements which have similar chemical properties but different physical properties. Carbon exists in two allotropic forms i.e., crystalline and amorphous form. The crystalline allotropes are Diamond, Graphite and fullerenes. The amorphous allotropes are coal, charcoal, lamp black etc. The correct answer is carbon dioxide. The carbon dioxide is a compound of carbon not an allotrope