Disinvestment of PSE's implies
Sale of equity shares to private sector / public
Closing down operations
Investing in new areas
Buying shares of PSE's
Hence, the correct answer is Sale of equity shares to private sector / public
Disinvestment refers to the process of selling equity shares of a public sector enterprise to the private or the public sector. Through disinvestment, the ownership of the government in a PSE gets diluted, and simultaneously, the quantum of shares held by the private sector in that enterprise increases.