Directions: Choose the appropriate word from the given options and fill in the blank.

Apart from the political leaders and high profile social activists, there are many ------------- heroes quietly working towards the realization of their aspirations.

Unsung heroes is a standard idiom referring to people who do great work without receiving recognition or fame. The phrase perfectly fits the context of ordinary people working quietly for social change while political leaders and activists get attention. Unknown and unfamiliar are too literal. Obscure suggests unclear or hidden, not unacknowledged.