Researchers from the United Kingdom studied the effect of two breathing frequencies on both performance times and several physiological parameters in front crawl swimming. The breathing frequencies were one breath every second stroke (B2) and one breath every fourth stroke (B4). Subjects were 10 male collegiate swimmers. Each subject swam 200 meters, once with breathing frequency B2 and once on a different day with breathing frequency B4.Step 1: Describe the design of this matched pairs experiment, including the randomization required by this design.A) Each swimmer swims one time using each breathing technique (B2 and B4). A coin is tossed to determine the order in which these techniques are used.B)Each swimmer swims two times using breathing technique B2 or B4. A coin is tossed to determine which technique is used.C)Each swimmer swims one time using breathing technique B2 or B4.D)Each swimmer swims two times using each breathing technique (B2 and B4). A coin is tossed to determine the order in which these techniques are used.Step 2: Could this experiment be conducted using a completely randomized design?A) It is not a completely randomized design.B) In a completely randomized design, the 10 male collegiate swimmers would be assigned randomly to the two treatments, 5 swimmers using technique B2 and the other 5 using technique B4.C) There is not enough information.D) In a completely randomized design, the 10 male collegiate swimmers would be assigned randomly to the two treatments, 6 swimmers using technique B2 and the other 4 using technique B4 or 4 swimmers using technique B2 and the other 6 using technique B4.Step 3: Are there any problems with having swimmers choose their own breathing frequency and then swim 200 meters using their selected frequency?A) If swimmers select their own technique, it would be a randomized controlled trial.B) If swimmers select their own technique, it would be a natural experiment.C) If swimmers select their own technique, it would be not an observational study.D) If swimmers select their own technique, it would be an observational study.