Dr. Adriana conducts a study to determine if players who wear a new type of soccer uniform made from a specially designed fabric will perform better in soccer matches. She recruits a professional soccer team to participate in her study. She randomly assigns half of the men to wear the new material uniforms made in the color blue and the other half to wear old-material uniforms made in the colored. Although the men know about the test, they are not told which of the two uniforms is made from the new material. They are asked to wear their assigned uniforms and score as many goals as possible in a game against one another. De Adriana notes the number of goals scored. Ultimately, the players who are wearing the old uniforms score more goal and therefore, win the game, Dr. Adriana speculates that the new uniforms are not more beneficial to performance than the old uniforms, but she decides to rerun the test a few more times. From a sdentific viewpoint, why was it important for Dr. Arlana to randomly assign the players to wear new or old uniforms?
A. She wanted to make sure that the uniforms do not affect the outcome of the game played by the players.
B. she wanted the players to feel they all had a chance of wearing their old uniforms, in which they would likely be more comfortable.
C. She wanted to ensure that the performance of the players will be uniformly improved by wearing their respective unitoring
D. She wanted to ensure that each player had an equal chance of wearing the new or old uniform.

The essence of random assignment or randomness in a scientific research is to avoid bais and ensure that all participants or subjects have equal chances of being in a particular category or class. In the scenario above, since half will wear the new uniform and half will el wear the old one, without random assignment, bias will set into the experiment as each of the players will not be equally likely to select either the old or new uniform. However, since the players were randomly assigned to the type of uniform, then they all have the same chance of picking either of the two categories of uniform.