Solution:The fastest and deepest geostrophic currents are found on the western boundaries of the ocean basins, and the currents on the eastern boundaries are more diffuse. Among the western boundary currents, the Gulf Stream is the largest current, not the Brazil Current. The Gulf Stream is an extensive current system that influences the climate of a large area. This system includes three currents:
(i) The Florida Current, between the Straits of Florida and Cape Hatteras.
(ii) The Gulf Stream, between Cape Hatteras and the Grand Banks.
(iii) The North Atlantic Current, east of the Grand Banks and up to the West European coast. The Brazil Current originates from the bifurcation of the South Equatorial Current after hitting the Brazilian coast near San Roque. One branch turns north and joins the North Equatorial Current, while the southern branch, known as the 'Brazil Current,' flows parallel to the South American coast up to South latitude.
The Canary, Benguela, and Humboldt currents are eastern boundary currents. Statements (A), (C), and (D) are correct, while statement (B) is incorrect. Therefore, option (a) is correct.