Critical Reasoning

A certain pharmaceutical firm claims that its dietary supplement, Dietol, is highly effective
in helping obese people lose weight and improve physical endurance. The company supports
this claim by providing the results of a recent experiment that involved over 800 subjects
suffering from obesity. During the 9-week experiment, each of the subjects was required to
take a regular dose of Dietol every day immediately after their daily 2-hour workouts
supervised by a professional fitness instructor. As a result of the experiment, the subjects lost
an average of 12 pounds of weight per person, and over 95% of all participants demonstrated
higher physical endurance. The answer to which of the following questions would be most
helpful in evaluating the conclusion of the pharmaceutical company?
A) What was the daily dose of Dietol that the subjects were required to take?
b) What was the maximum weight lost by any participant during the 9-week program?
c) What would be the average weight loss and the improvement in endurance in a group of
subjects with similar characteristics involved in the same physical fitness program but not
taking Dietol?
d) What was the average age among the subjects participating in the experiment?
e) Did the majority of subjects experience a significant improvement in physical strength?

OA is C
Urgent analysis and Explanation needed, please. An expert should please help out.Thanks in advance

Reasoning behind this argument is :

Argument says -> X leads to Y [ONLY Option to Y]

To evaluate this argument ask this question
Weather A also leads to Y? [Yes can weaken and No can Strengthen]

A) What was the daily dose of Dietol that the subjects were required to take? --> 10,20,30 --> none of the answer matters
b) What was the maximum weight lost by any participant during the 9-week program? - 1 or 20 or 100 --> none of the answer matters
c) What would be the average weight loss and the improvement in endurance in a group of
subjects with similar characteristics involved in the same physical fitness program but not
taking Dietol? ----C is the only answer that is similar to question "Weather A also leads to Y? [Yes can weaken and No can Strengthen]" if ONLY heath prog in question helps someone loose more wt, then it strengthens, if other similar Prog can attain the same results, it weakens the argument.
d) What was the average age among the subjects participating in the experiment? -60 or 30 doesn't matter
e) Did the majority of subjects experience a significant improvement in physical strength? Yes / No doesn't matter