Answer:
Chronologically
Step-by-step explanation:
Chronologically - putting events in order from when they occurred.
The author puts events in chronological order.
When an article is organized chronologically you can almost create a timeline with the events:
Gertrude Belle Elion was born on Jan. 23. 1918.
She graduated with a degree in biochemistry in 1937
She earned a master's degree in 1941.
Reasons it can't be the other answer choices.
Interviews and research - if the author organized this article using interviews and research there would likely be sourcing of the research and interviews. There is no sourcing so the author could not have used interviews and research.
Cause and effect - Although there is one cause and effect situation present in this article, the author did not organize the whole article using cause and effect situations so the author likely did not organize information in this article using cause and effect.
Problem-solution - when an author uses problem - solution to organize their article the article usually ends in the a solution to the problem. Although there was some type of problem ( Gertrude not being able to obtain a graduate research position, nor her doctorates ), the article did not end in the problem being solved. So the author likely did not use problem - solution