The type of natural selection demonstrate is B. stabilizing selection.
There are different types of natural selections, each affecting the population density of a specific allele in a different way. In stabilizing selection, the non-extreme trait is maximized. This is seen in the curve as there is less population observed at the extreme ends of the spectrum but a greater population lying in the average, less extreme zone.
The diaphragm,
During inhalation, the diaphragm is contracted which increases the volume of the lung cavity. During exhalation, the diaphragm is relaxed which decreases the volume of the lung cavity
It is incorrect its B.tropism