Multiple choice general knowledge culture Bhishma was Santanu's _th son. 6 7 8 9 Reveal answer Fill a bubble to check yourself C Correct answer Explanation Bhishma (Devavrata) was Santanu's eighth son - his mother Ganga had drowned the first seven sons immediately after birth. Bhishma was the only son Ganga allowed to live, which led to his famous vow of celibacy.