Separation of Substances

Paheli asked for a glass of water from Boojho. He gave her a
glass of ice cold water. Paheli observed some water droplets on
the outer surface of the glass and asked Boojho how these
droplets of water were formed? Which of the following should
be Boojho’s answer?
(a) Evaporation of water from the glass.
(b) Water that seeped out from the glass.
(c) Evaporation of atmospheric water vapour.
(d) Condensation of atmospheric water vapour.