The Government empowered itself to attach the assets of all the scam suspects.

Answer: Option C

Attach : seize (a person or property) by legal authority.
Detach : disengage (something or part of something) and remove it.
Donate : give (money or goods) for a good cause, for example to a charity.
Return : give, put, or send (something) back to a place or person.
Release : allow or enable to escape from confinement; set free.

Antonym of Attach is Return