Written Lifeguarding Practice Test

When giving chest compressions, it is important to place the heel of one hand on the center of the chest, with the other hand on top. This positioning helps ensure that enough pressure is being applied to the sternum, which is necessary for effective chest compressions. Option A is incorrect because encircling the chest with thumbs centered at the nipple line does not provide enough force to compress the chest. Option C is incorrect because the hands should overlap and not be placed side-by-side. Option D is incorrect because three fingers do not provide enough surface area to effectively compress the chest.