The day on which the Partition of Bengal took effect—16 October 1905—was…

Concept

A historical observance is identified by the commemorative meaning assigned to the day, while boycott and strike describe methods of protest.

The label of the day must therefore be distinguished from the actions that people performed during the observance.

Application

The Partition of Bengal took effect on 16 October 1905. Contemporary nationalist accounts describe the date as a day of national mourning, marked by fasting, processions, and Rakhi-bandhan.

The Hindi word Shok means mourning, so it supplies the commemorative meaning asked for in the stem.

Contrast

• Boycott was the economic strategy of refusing foreign goods during the anti-partition movement.

• Hartal was the protest practice of closing shops and suspending work.

• Shok names the collective grief with which the day itself was observed.

• More than one of the above would require at least two listed terms to name the commemorative category; associated protest methods do not satisfy that requirement.

• None of the above is excluded because an offered term directly expresses the recorded observance.

Cross-check

Contemporary recollections and standard histories consistently describe 16 October 1905 as a day of national mourning; this agrees with Shok.

Therefore, the answer is Shok (mourning).