Which of the following came first in the scientific study of living organisms?

A. light microscope

B. Cell Theory

C. electron microscope

D. model of DNA

A. Light microscope

The light microscope is said to have been invented in the late 16th century, hundreds of years before any of the other mentioned options. The cell theory was developed in the 1830s, while the discovery of the DNA molecule, as well as the creation of the electron microscope, occurred in the mid-1900s.