Three Questions!
Please note that three different and distinct questions were posed to John the Baptist and to which he gave three emphatic "NO'S" as answers. To recapitulate:-

1) ART THOU THE CHRIST?
2) ART THOU ELIAS?
3) ART THOU THAT PROPHET?
But the learned men of Christendom somehow only see two questions implied here. To make doubly clear that the Jews definitely had T-H-R-E-E separate prophecies in their minds when they were interrogating John the Baptist, let us read the remonstrance of the Jews in the verses following:
"AND THEY ASKED HIM, AND SAID UNTO HIM, WHY BAPTIZEST THOU THEN, IF THOU BE
a) NOT THAT CHRIST,
b) NOR ELIAS,
c) NEITHER THAT PROPHET?" (John 1:25)
The Jews were waiting for the fulfillment of THREE distinct prophecies: One, the coming of CHRIST. Two the coming of ELIAS, and Three, the coming of THAT PROPHET.