You are given a science question (easy-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.

Cells come in two basic types, prokaryotic and eukaryotic. Which cell structure is found in both prokaryotic and eukaryotic cells?  
 (A) vacuole (B) nucleoid (C) mitochondrion (D) cytoplasm
D

In what type of rock would a geologist most likely find evidence of ancient life?  
 (A) sedimentary (B) foliated (C) metamorphic (D) volcanic
A

The following waste materials are buried in a landfill. Which will break down most quickly?  
 (A) steel (B) plastic (C) glass (D) paper

D