سوال ۱۹ کنکور ارشد فیزیک ۱۴۰۵

Read the passage and answer the question.

PASSAGE: Feynman's stature among physicists transcended the sum of even his sizable contributions to the field. His bold and colorful personality, unencumbered by false dignity or notions of excessive self-importance, seemed to announce: "Here is an unconventional mind." He was a master calculator who could create a dramatic impression in a group of scientists by slashing through a difficult numerical problem. His purely intellectual reputation became a part of the scenery of modern science. His fellow physicists admired him for his flashes of inspiration and other qualities as well such as a faith in nature's simple truths, a skepticism about official wisdom, and an impatience with mediocrity.

When Feynman died in 1988 after a long struggle with cancer, his reputation was still confined to the scientific community; his was not a household name. Many Americans had seen him for the first time when, already ill, he served on the presidential commission that investigated the 1986 explosion of the space shuttle Challenger. He conducted an illustrative demonstration at a televised hearing, confronting an evasive NASA witness by dunking a piece of rubber seal in a glass of ice water, proving how predictable the failure of the booster rocket's rubber seal was on the freezing morning of Challenger's launch.

Which of the following techniques is used in the passage?