The magnification of a telescope can be modified by changing the wavelength eyepiece focal length of the objective objective lens

answer; /// the shaft of the hair consists of dead cells;

option d : from a warmer substance to a cooler substance

according to second law of thermodynamic, heat flows from higher to lower temperature region. heat is the transfer of energy from an object at higher temperature to an object at a lower temperature. so energy flows from warmer to colder objects.