Answer
The answer is Sri Lanka. Shahid Afridi, the former Pakistani all-rounder, holds the record for the fastest century in One Day International (ODI) cricket. Afridi achieved this remarkable feat against Sri Lanka in 1996 during the second ODI of a three-match series in Nairobi, Kenya. He smashed an incredible hundred off just 37 balls, breaking the previous record held by New Zealand's Nathan Astle.