Read this poem:

How like a winter hath my absence been
From thee, the pleasure of the fleeting year!
What freezings have I felt, what dark days seen!
What old December's bareness every where!
And yet this time removed was summer's time;
The teeming autumn, big with rich increase,
Bearing the wanton burden of the prime,
Like widow'd wombs after their lords' decease:
Yet this abundant issue seem'd to me
But hope of orphans and unfather'd fruit;
For summer and his pleasures wait on thee,
And, thou away, the very birds are mute;
Or, if they sing, 'tis with so dull a cheer
That leaves look pale, dreading the winter's near.

Where does the tone shift in the poem?

A. The tone shifts in the last two lines.
B. The tone shifts in the second stanza.
C. The tone shifts in the last line.
D. The tone shifts in the third stanza.

This excerpt comes from William Shakespeare´s Sonnet 97, and which was published around 1609. When analyzing the stanzas, you realize that in the first quatrain of the poem, the speaker is merely talking about having been forced to go through a process of separation from someone that is loved, and therefore, the tone is saddening, almost like how winter´s effects look. Then, he goes on to say that maybe it is not so saddening, like trying to look on the brighter side of things, by comparing the feelings more to autumn, or late summer.

But in the final part of the poem, the speaker goes to deny his optimism about this separation, making the poem seem really sad, even more so than at the start. Now, it is almost tangible, in the last two lines, the sadness felt for the separation. So much so, that even if there were a single joyful thing, like the song of a bird, it would still be with "so dull a cheer/ That leaves look pale, dreading the winter´s near."