Which of the children does the ghost say we should beware the most ?

In
stave 3, "The Second Of The Three Spirits," of 's , the Ghost of
Christmas Present conducts Ebenezer Scrooge throughout London, showing him vignettes of the
Cratchit family's Christmas dinner and Scrooge's nephew Fred's Christmas party. The Ghost also
takes Scrooge out on the moors to listen to miners sing Christmas songs and wish each other a
"Merry Christmas" and whisks Scrooge out to a ship at sea where sailors speak kinds
words to each other and hum Christmas tunes to themselves.

Much they saw, and far they went, and many homes they visited, but always with a happy
end. The Spirit stood beside sick beds, and they were cheerful; on foreign lands, and they were
close at home; by struggling men, and they were patient in their greater hope; by poverty, and
it was rich. In almshouse, hospital, and jail, in miserys every refuge, where vain man in his
little brief authority had not made fast the door, and barred the Spirit out, he left his
blessing, and taught Scrooge his precepts.

The last visit
is to a children's Twelfth Night party, just fifteen minutes before midnight: the time the Ghost
said that his life would end. Scrooge was thinking to himself that although he hadn't aged even
a little, the Ghost had become considerably older, when Scrooge notices something poking out
from under the Ghost's robe.

Forgive me if I am not
justified in what I ask, said Scrooge, looking intently at the Spirits robe, but I see
something strange, and not belonging to yourself, protruding from your skirts. Is it a foot or a
claw?

The Ghosts lifts his robe, revealing two children,
a boy and a girl, looking "wretched, abject, frightful, hideous, miserable." They
kneel down at the Ghost's feet and grab at his robe.

Scrooge is frightened
and appalled by the appearance of the children, and he backs away from them.

"This boy is Ignorance. This girl is Want. Beware them both,
and all of their degree, but most of all beware this boy, for on his brow I see that written
which is Doom, unless the writing be erased."

Have they no refuge or
resource? cried Scrooge.

Are there no prisons? said the Spirit, turning on
him for the last time with his own words. Are there no workhouses?"

Scrooge is struck by the thought of his own ignorance, which led to
these children's deplorable condition and to the wretched condition of other men, women, and
children whom Scrooge has ignored throughout his life.