Why does the narrator include the following detail in the story?

Echo silently followed him. “How I wish I could talk to him," she thought.

A). The narrator wants the reader to understand Echo's
love for herself.
B). The narrator wants the reader to know how Echo feels
about Narcissus.
C). The narrator wants the reader to know how Echo will
tell Narcissus she loves him.
D). The narrator wants the reader to understand why Echo
can only repeat other characters' words.