Carbon may be stored in sedimentary rock for millions of years.
Carbon is the fuel source.
A fuel source may be stored in sedimentary rock for millions of years.
What may be stored in sedimentary rock for millions of years.

A) Sand castles
B) Chemical energy
C) heat energy
D) Millions of dollars.
E) A fuel source.
F) Energy.
G) In sediment
H) Stored animal fur.