The Indian Constitution provides Fundamental Rights to citizens.
Article 15 deals with prohibition of discrimination.
It says that the State shall not discriminate against any citizen on grounds only of:
\[
\text{religion, race, caste, sex, place of birth, or any of them}.
\]
Therefore, the statement given in the question is directly related to Article 15.
Article 21A deals with the right to education.
Article 19 deals with freedoms such as speech, expression, movement, association, and profession.
Article 35 is related to legislation for giving effect to certain fundamental rights.
Thus, the correct constitutional article is:
\[
\text{Article 15}.
\]