Why does Tennyson most likely make the fifth stanza longer than the third stanza of "The Charge of the Light Brigade"?

to make each stanza in the poem slightly longer than the previous one
to show that the fifth stanza is more critical in understanding the poem
to draw the reader’s focus to the fourth stanza where the battle occurs
to highlight the aftermath of the fierce battle waged in the fourth stanza

A.

As we know, rhyme is a correspondence of sounds in the endings of words. In a simpler definition, rhyme happens when words have the same final sound. To determine the rhyme scheme in a poem, all we need to do is look at the last word of each line. We then attribute a letter to represent the final sound of that word. The first final word of the first line is always represented by the letter A. Therefore,

Forward, the Light Brigade! A

From there on, every new final sound that appears receives a new letter according to the alphabetic sequence (B, C, D etc.) If a sound is repeated, it receives the same letter as was previously used. Notice how it happens:

Forward, the Light Brigade!” A

Was there a man dismayed? A

Even though spelled differently, brigade and dismayed end with the same sound and, thus, are attributed the same letter. With those instructions in mind, we can easily determine the rhyme scheme of the whole stanza:

“Forward, the Light Brigade!”  A

Was there a man dismayed?  A

Not though the soldier knew  B

Someone had blundered.  C

Theirs not to make reply,  D

Theirs not to reason why,  D

Theirs but to do and die.  D

Into the valley of Death  E

Rode the six hundred. C