A poet writes the following lines:

The phantom happiness I sought
O'er every crag and moor;
I paused at every postern gate,
And knocked at every door,

What is the effect of the word phantom in the first line?

A: It makes their happiness seem imaginary.
B: It makes their happiness seem easy to reach.
C: It makes their happiness seem genuine.
D: It makes their happiness seem upbeat.