Select the option that can be used as a one-word substitute for the given group of words.
A detailed description of a series of real or fictional events taking place over a long period of time

Correct option is C

The correct one-word substitute for "A detailed description of a series of real or fictional events taking place over a long period of time" is Saga.

• Saga: A long, involved story, account, or series of incidents, often spanning generations or a long period of time.
• Hindi meaning: गाथा।
• Example: The novel was a family saga, telling the tale of several generations.

Meanings of all other options:

• Witness: A person who sees an event, typically a crime or accident.
• Journal: A record of daily events or thoughts, typically written down.
  
• Case study: A detailed examination of a particular instance or event for research purposes.