A medical research lab in Europe is studying a drug’s absorption in the blood. Another lab in Japan is trying to delay the elimination of this drug from the blood so that it can act in the body for a longer period of time. Based on this information, it can be concluded that scientific knowledge progresses due to the efforts of scientists
from different social and ethnic backgrounds.
from the most prestigious universities of the world.
who possess a high degree of efficiency.
who possess a high degree of skepticism.

The correct answer is From different social and ethnic backgrounds.

Explanation:

The purpose of science studies is to gain an understanding of specific phenomena and use this in the benefit of the world or humanity. Moreover, science is guided by objective methods and these are applied all around the world. This feature allows scientists from all kinds of social and ethnic backgrounds to study the same phenomena and obtain similar results, which is essential for the progress of scientific knowledge. This is exemplified by two different labs in two different countries studying drug absorption because the results of these two studies can be analyzed together to understand drug absorption.

In this context, one factor that contributes to the progress of scientific knowledge is the effort of scientists "from different social and ethnic backgrounds".