Physical regions marked as 1, 2, 3, and 4 on the given map are respectively

(a) Andes, Brazilian Shield, Guyana Highlands and Amazon Basin
(b) Andes, Guyana Highlands, Brazilian Shield and Amazon Basin
(c) Amazon Basin, Guyana Highlands, Brazilians Shield and Andes
(d) Guyana Highlands, Brazilian Shield Andes and Amazon Basin