Question

the chemical is also a radioactive isotope, which means it can be visualized using a pet scan. source: a deadly wandering: a mystery, a landmark investigation, and the astonishing science of attention in the digital age in this sentence, visualized means: combined into one made indistinct or blurred improved in quality made viewable

Explanation:

The term "visualized" in the context of a PET - scan means to make something visible or observable. A PET - scan is used to create images of the inside of the body, so the radioactive isotope can be made viewable through this scan.

Answer:

D. made viewable