Reducing character is directly proportional to the
tendency to lose electrons
Explanation for the correct option: (C) tendency to lose electrons
Reducing character refers to a substance's inclination to decrease another substance, while basicity refers to a compound's ability to easily give up hydrogen atoms or electrons.
Hence, Reducing character is directly proportional to the tendency to lose electrons.
Explanation for the incorrect options:
(A) The non-metallic character is the tendency of an element to accept electrons and form negative ions or anions.
(B) Electronegativity is a chemical property that describes the tendency of an atom or a functional group to attract electrons toward itself.
(D) The tendency to gain electrons is called electronegativity.
Hence, the correct option is (C).