You are given a background paragraph that describes one or more causal or qualitative relationships such as a relationship in economics or a scientific law and a story that makes use of the concepts or the relationship described in the provided paragraph. You are also given a question about the story that requires an understanding of the relationship described in the background paragraph and the story. You need to come up with an answer to the given question; the answer will be a span from either the question or the story. In order to correctly answer the given question, you need to understand the relationship mentioned in the background paragraph and should be able to use it to understand that in the story. Your answer can not consist of any word that is not mentioned in any of these: the background paragraph, the story, or the question. You can directly copy and paste a span from the story or the question while answering the given question.

Background Paragraph: The stronger of two acids will have a higher Ka than the weaker acid; the ratio of hydrogen ions to acid will be higher for the stronger acid as the stronger acid has a greater tendency to lose its proton. Because the range of possible values for Ka spans many orders of magnitude, a more manageable constant, pKa is more frequently used, where pKa = −log10 Ka. Stronger acids have a smaller pKa than weaker acids. Experimentally determined pKa at 25 °C in aqueous solution are often quoted in textbooks and reference material. 
Story: Jacob and Thomas were conducting an experiment in a chemistry class. The goal of the experiment was to identify the strength of unknown acids by examining the products formed in a chemical reaction. After they completed the experiment, Jacob concluded that he was given a strong acid, while Thomas concluded that he was given a weak acid. 
Question: Which person's acid, Jacob's or Thomas's, will have a larger pKa?
Thomas's.

Background Paragraph: Klinefelter's syndrome is caused by the presence of one or more extra copies of the X chromosome in a male's cells. Extra genetic material from the X chromosome interferes with male sexual development, preventing the testicles from functioning normally and reducing the levels of testosterone. Triple X syndrome (trisomy X) results from an extra copy of the X chromosome in each of a female's cells. Females with trisomy X have a lower IQ than their siblings. Turner syndrome results when each of a female's cells has one normal X chromosome and the other sex chromosome is missing or altered. The missing genetic material affects development and causes the characteristic features of the condition, including short stature and infertility. 
Story: David is a physician with the children's hospital. He is seeing four patients, patient A, patient B, patient C, and patient D. Patient A is a male with Klinefelter's syndrome. Patient B is female with Turner syndrome. Patient C is a male and does not have any of these illnesses. Patient D is a female and she too does not have any of these illnesses. 
Question: Which patient would have higher level of testosterone, patient A or patient C?
patient C.

Background Paragraph: In exercises such as weight lifting, skeletal muscle contracts against a resisting force (see Figure below ). Using skeletal muscle in this way increases its size and strength. In exercises such as running, the cardiac muscle contracts faster and the heart pumps more blood. Using cardiac muscle in this way increases its strength and efficiency. Continued exercise is necessary to maintain bigger, stronger muscles. If you don’t use a muscle, it will get smaller and weaker—so use it or lose it. 
Story: Michael has become bored with his passive life style, and has decided to take up weight lifting as a hobby. He begins to exercise with weights several times a week. Michael's brother, Robert, isn't as motivated as Michael though. Robert decides to continue being mostly inactive and only exercises with weights every couple of months. 
Question: Who will increase the strength of their muscles less?

Robert.