Explanation:

• Correct Option: (a) Explanation:  Option (a) is correct Supplementary notes: Ocean Currents  Ocean currents are the continuous, predictable, directional movement of seawater driven by gravity, wind (Coriolis Effect), and water density.
•  Ocean water moves in two directions: horizontally and vertically.
• Horizontal movements are referred to as currents, while vertical changes are called upwelling or downwelling.
•  This abiotic system is responsible for the transfer of heat, variations in biodiversity, and Earth’s climate system.
•  Winds, water density, and tides all drive ocean currents.
• Coastal and sea floor feature influence their location, direction, and speed.
• Earth’s rotation results in the Coriolis Effect which also influences ocean currents.
•  Large-scale surface ocean currents are driven by global wind systems that are fueled by energy from the sun.
• These currents transfer heat from the tropics to the Polar Regions, influencing local and global climate. Water with high salinity is denser than water with low salinity.
• Differences in water density affect the vertical mobility of ocean currents.
• Denser water tends to sink whereas warm water tends to rise.
• Cold-water ocean currents occur when the cold water at the poles sinks and slowly moves towards the equator.
• Warm-water currents travel out from the equator along the surface, fl owing towards the poles to replace the sinking cold water.
• Ocean currents are generally referred to by their “drift”.
• Ocean currents are stronger at the surface and may attain speeds over 5 knots.
• At depths, ocean currents are generally slow with speed less than 0.5 knots.