Which of the following rivers is a tributary of the Ganga in India?

All of the given options are correct: the Son, the Yamuna and the Gomti all feed the Ganga. The Yamuna, its largest right-bank tributary, joins it at Prayagraj; the Gomti, rising near Pilibhit, flows past Lucknow and joins it near Ghazipur; and the Son, rising on the Amarkantak plateau, joins it from the south above Patna. Choosing any single river leaves out the other two.