The correct answer is A. The speaker and his companion are sampling items but not paying for them. His companion is the American poet Walt Whitman. He's portrayed as a strong and powerful figure who is able to avoid the payment demands of the supermarket and capable of tasting food, enjoying the natural items offered there but he doesn't pay for them.
Whitman was admired by Ginsberg, he represented talent and freedom for the author of this poem. That is why he presents Whitman in the supermarket defying all laws of capitalism tasting vegetables and not paying for them, as if they were in a dreamed land.