An ice fisherman has fallen through the ice. In response to the cold water, sensors in the man's skin send a "cold" signal to the in the man's brain, which in turn sends signals to muscle cells to begin to contract. As a result of this process, the fisherman begins to shiver

Hypothalamus

Explanation:

homeostasis in terms of body temperature involves maintaining a constant temperature as much as balancing the internal and external temperature of man. For humans, normal temperature is about 98.6°F (37°C). When your hypothalamus senses that you’re too hot, it sends signals to your sweat glands to make you sweat and cool you off. When the hypothalamus senses that you’re too cold, it sends signals to your muscles that make your shiver and create warmth. This is called maintaining homeostasis. The hypothalamus also maintains homeostasis in lots of other ways, such as by controlling your blood pressure.

Vigorous shivering increased the body's heat energy.

answer; /// i believe the correct answer is (thrombocytopenia); (a)

d concave shape of wave rock

explanation:

the concave shape of wave rock is a very good evidence that supports the evolution of earth due to chemical weathering. if we talk about structure of   wave rock, studies have estimated that it is around 2.7 billion years old. it also serves as the foundation of evidence that it was the place where australian continent began to form.

how the structure of wave rock was created?

studies suggest that structure of wave rock was created when the surrounded area was started to weather due to which deposition of material started on the part of land which now contains wave rock.

the structure of wave rock is considered to be one of the best-known landforms in australia. at the height of around 15 cm, there can be found flared slopes which formulate the margins of hyden rock. it is now assumed by geologists that wave rock was created by subsurface water-induced weathering and not by glaciers, waves or wind.

due to deposition of material over the period of long time, the wave rock became tougher and tougher due to weathering from surrounding terrain. this makes it a physical evidence that supports   the evolution of earth due to chemical weathering.

hope it !