Where are fossils generally found?

Correct answer: In layers of rocks

When organisms die, their remains may be buried under sediments such as mud or sand. Over a very long period, pressure and mineral deposition can preserve these remains or impressions in sedimentary rock layers. Therefore option A is correct. Milk, human blood, and ordinary tree leaves are not the geological settings in which fossils are generally preserved; the word “always” also makes option D incorrect.