Forensic scientists immerse glass evidence into a medium to determine its refractive index. Which medium is usually used for determining the refractive index? A. water B. air C. oil D. gel

not always but somethings can be reproduced in a laboratory.

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.