Correct Option (d):
- Diamond is an allotrope of carbon, composed entirely of carbon atoms.
- Marble is primarily composed of calcium carbonate (CaCO₃), making calcium its key elemental constituent.
- Sand predominantly consists of silicon dioxide (SiO₂), with silicon as the main element.
- Ruby is a variety of corundum, which is aluminium oxide (Al₂O₃), thus containing aluminium as its principal metallic element.
Incorrect Options:
Options (a), (b), and (c) are incorrect as they contain one or more mismatches between the naturally occurring substance and its primary elemental composition, contrary to the established chemical facts.