Whats the shape to finding a four leaf clover?

According to New York Times, Don’t get up close and start counting individual leaves. Instead, visually skim for what Hirst calls “ruptures in the pattern” — a four-leaf clover makes the shape of a square, while the typical three-leaf version appears as a triangle. Imprint the four-leaf image in your mind until you can see it even when you close your eyes.

Hope this helps :)

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.