I think the correct answer from the choices listed above is option A. A control group is missing that would improve the scientific design. This control group should be done at a regular dosage prescribed. This is important to minimize errors in the experiment.
The right answer is B. Reinforced Sole Boots.
Reinforced soled boots protect your feet from falling objects, sharp objects on the ground and uneven terrain during work. Different models are proposed for your comfort: boots in PVC or leather, filled or not, and waders for working in the water! Reinforcements at the top of the foot ensure you work safely.