Plants excrete water droplets through hydathodes through a process called: 

Plants excrete water droplets through hydathodes and the process is known as guttation.

Hydathodes are open pores. These are present at the margins of the leaf epidermis.
It is the pore at which small xylem vessels of veins of leaves open.
When there is positive root pressure of water, the water comes out of these pores by the process called guttation.

Hence, the correct answer is guttation.