Concept:Fardul kifayah is a collective obligation; if some Muslims perform it, the rest are absolved.
Explanation:Salatul Janazah, the funeral prayer, is an example of fardul kifayah.
It is offered when a Muslim dies.
It is a duty upon the Muslim community of that locality, not just one individual.
If a group performs it, the obligation is fulfilled.
Among the given options, only Janazah prayer has this collective obligation.
Duha, Zuha, and Tawawih are all optional or voluntary prayers.
Answer:C. Janazah