Correct Option
The correct option is (a).
Explanation
The Hydrological Cycle (Water Cycle), which describes the continuous movement of water on, above, and below the surface of the Earth. In this cycle, Earth is treated as a closed system regarding the mass of water.Statement 1: Correct
According to the principles of the hydrological cycle, the Earth is a closed system. This means that the total volume of water on Earth remains constant. Water is neither added nor subtracted; it merely changes its state (solid, liquid, gas) and circulates between the atmosphere, oceans, and land.
Statement 2: Incorrect
While it is true that oceans cover approximately 71% (roughly two-thirds) of the Earth's surface, the second part of the statement is factually flawed. Oceans contain saline water (approximately 97.3% of total water), not fresh water. Fresh water accounts for roughly 2.7% of the total water on Earth. The statement incorrectly associates oceans with fresh water accounting. The statistic "less than 1%" typically refers to the portion of fresh water that is accessible for human use (groundwater, rivers, lakes), not the content of oceans.
Statement 3: Incorrect
In the context of the global hydrological cycle, water is not constantly added from outer space. The cycle operates on the premise that water circulates within the Earth's system without external addition or loss of volume.
Key Takeaway: The Earth is a closed system for water; the total volume of water remains constant, while its distribution changes across oceans, the atmosphere, and landforms.