A heart beat, breathing, and moving ;)
The correct answer would be
C.) <span>Polio Vaccination.</span>
Water<span> issuing from a </span>hot spring<span> is heated geothermally, that is, with heat produced from the Earth's mantle. ... The rate of temperature increase with depth is known as the geothermal gradient. If </span>water<span> percolates deeply enough into the crust, it will be heated as it comes into contact with </span>hot<span> rocks.</span>