The correct options are
A Discrimination happens when people are forced to take up menial jobs.
B Discrimination happens when people ban certain communities from entering a public place.
C Discrimination happens when certain castes are prevented from entering temples.
D Discrimination happens when people are denied access to public water taps.
Discrimination happens when we act on our prejudices and stereotypes. All these examples are instances of discrimination. The upper castes discriminated against the lower castes and denied them equal rights and opportunities.