Which one of the following rivers joins the Ganga river directly while the other three join the Yamuna river ?

The Ganga river system comprises numerous tributaries originating from both the Himalayas and the Peninsular plateau. The Son river is a major right-bank tributary of the Ganga, originating from the Amarkantak highlands in the Maikala range and joining the Ganga directly near Patna [6]. In contrast, the Betwa, Ken, and Sind are primary right-bank tributaries of the Yamuna river [1][t1]. The Yamuna itself is the longest tributary of the Ganga, meeting it at Prayagraj (Allahabad) [2][t5]. While the Chambal, Sind, Betwa, and Ken flow northward from the Vindhyan and Satpura ranges to join the Yamuna, the Son follows a similar northward path but bypasses the Yamuna to discharge its waters directly into the Ganga [3][c4]. Therefore, among the given options, only the Son joins the Ganga directly.

Sources

1. [2] https://indiawris.gov.in/wiki/doku.php?id=sone_basin
2. [6] CONTEMPORARY INDIA-I ,Geography, Class IX . NCERT(Revised ed 2025) > Chapter 3: Drainage > The Ganga River System > p. 20
3. [1] INDIA PHYSICAL ENVIRONMENT, Geography Class XI (NCERT 2025 ed.) > Chapter 3: Drainage System > Do you Know? > p. 22
4. [3] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 3: The Drainage System of India > The Yamuna River > p. 13