Answer:
C. cytosine and guanine
Step-by-step explanation:
A.estrogen and testosterone - estrogen and testosterone are found in many mammals, but are not found in, for example, plants or bacteria.
B.hemoglobin and lymphocytes - hemoglobin is a protein found in a red blood cells. Lymphocytes white blood cells Again, they are found in organisms with closed circulatory systems and immune systems, but not simple organisms such as insects.
C. cytosine and guanine - these are the building blocks of DNA, which is a component in all living cells. Therefore, they are found in all living organisms
D.cellulose and chlorophyll - cellulose and chlorophyll are specific to plant cells.