During redox reactions:

A. protons from one molecule replace the electrons lost from another molecule.
B. the loss of electrons from one molecule is called reduction.
C. electrons are lost from one substance and added to another substance.

C. electrons are lost from one substance and added to another substance.

Explanation:

Electrons are transferred from one reactant to another and the oxidation states/oxidation number of certain atoms are changed.

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.