Answer the following question: Fact 1: Oil is formed by layers of sediment pushing down on decomposing algae. Fact 2: When the algae dies it is decomposed by bacteria. Given the two facts above, oil is formed by layers of sediment pushing down on what?

Available options:
1). bacteria;
2). nutrients;
3). amoebae;
4). tunicates;
5). oysters;
6). coral reefs;
7). mussels;
8). Bodily water;
Answer:
1).