Answer: SEX TRAFFICKING
Explanation: Sex trafficking is an activity in which people are recruited, harboured, transported, bought, or kidnapped for the purpose of sexual exploitation including forcing sexual act on a person held as a sex slave.
One of the major reasons for sex trafficking is FINANCIAL GAIN.
Critical (feminist) persons who believe in bringing about the equality (of women and men) in all aspects of public and private life have viewed sex slave as a means to exploit women for financial gain.