How do the poetic devices used in this stanza enhance its meaning?

laugh and the world laughs with you,
weep, and you weep alone;
the good old earth must borrow its mirth,
but has trouble enough of its own
(from "solitude" by ella wheeler wilcox)

they emphasize the selfish nature of human beings.

they exaggerate the troubles of the world.

they imply that everyone must struggle on their own.

they explain that everyone struggles to be happy.