The correct answer is option 1, i.e A-4; B-3; C-2; D-1.
The correctly matched tribes and their region are as follows:
Khirghiz tribe of Siberia : They are Turkic ethnic group native to Central Asia, primarily Kyrgyzstan and parts of central Siberia.
Pigmies tribe of Congo : They are a group of hunter gatherers native to Central Africa, mostly the Congo Basin.
Bedouin tribe of Saudi Arabia : They are nomadic pastoralists of Arabian Peninsula who relied on their herds of goats, sheep, and camels for meat, milk, cheese, etc.
Ainu tribe of Japan : They are an indigenous ethnic group of people who live in Hokkaido in Japan.