The rhetorical technique used in this excerpt is

A. Shift

Explanation:

The above option is the correct answer.

The rhetorical technique used in this excerpt is a rhetorical shift. A rhetorical shift is known to occur when someone (a speaker or a writer) alter the tone or style in a speech or written work.

In the given speech, we can see that there was a shift that occurred. The speaker started off by pointing out what the Allies experienced during the first four years of the war. Then when he was about to make a shift, used the phrase "And yet" to transit in order to reveal that in the end of the first four years, the morale of Allies remained higher than that of the Germans.