The flight was delayed because of bad weather.

Answer: Option C

Delayed : make (someone or something) late or slow.
Quickened : make or become faster or quicker.
Released : allow or enable to escape from confinement; set free.
Expedited : make (an action or process) happen sooner or be accomplished more quickly.
Triggered : cause (a device) to function.

Antonym of Delayed is Expedited