Answer:
The irony at the end of the poem "The Road Not Taken" by Robert Frost lies in the speaker's regret at not being able to take both roads. The speaker says, "Oh, I kept the first for another day!" indicating that he wishes he had chosen differently. This is ironic because throughout the poem the speaker is trying to decide which road to take, and he ultimately chooses one, but then regrets not being able to take the other. This regret shows that the speaker could have chosen either road and the outcome would have been the same. Examples from the poem that support this include:
"Two roads diverged in a wood, and I— I took the one less traveled by, And that has made all the difference."
This shows that the speaker was aware that either road could lead to an exciting journey, but he still chose only one.
"I shall be telling this with a sigh Somewhere ages and ages hence: Two roads diverged in a wood, and I— I took the one less traveled by, And that has made all the difference."
This shows that the speaker is already regretting his decision and looking back on the situation with a sigh.