With reference to the Himalayan rivers joining the Ganga downstream of Prayagraj from West to East, which one of the following sequences is correct ?

Lists important left‑bank tributaries of the Ganga as Ramganga, Gomati, Ghaghara, Gandak, Kosi, Mahananda—identifying these rivers as left‑bank Himalayan tributaries downstream of the Yamuna (Prayag).

A student could place these named tributaries on a map east of Prayag to check their relative west–east sequence.

Gives a named list of large left‑hand tributaries (Sharda, Kali, Gomti, Ghagra, Gandak, Kosi, Mahananda), which appears ordered geographically along the Ganga system.

Treat the list as a west→east ordering cue and compare each river's mouth location on a map to test the proposed Ghaghara–Gomati–Gandak–Kosi sequence.

States Gandak enters the plains in Champaran (Bihar) and joins the Ganga at Sonpur opposite Patna, giving a concrete downstream (eastern) location for Gandak's confluence.

Use Patna/Sonpur as a fixed point on a map to judge whether Ghaghara and Gomati confluences lie west of Gandak and whether Kosi lies east.

Notes Ghaghara, Gandak and Kosi rise in Nepal Himalaya and are major Himalayan tributaries that flood northern plains—grouping Ghaghara with Gandak and Kosi as neighboring Nepal‑born tributaries.

Map the Nepal origins and follow each river's course into the Indian plains to infer their lateral ordering along the Ganga.

States Gandak and Kosi are main left‑hand tributaries in the Middle Ganga Plain, indicating both join the Ganga in roughly the same lower‑middle reach (useful for relative placement).

Compare the described Middle Ganga Plain confluence zone with known locations of Ghaghara and Gomati to test relative west–east positions.