Which among the following combination is present in higher amount in hard water?

Calcium and magnesium

The correct answer is option 3. Calcium and magnesium.

Hard water primarily contains dissolved calcium \((Ca^{2+})\) and magnesium \((Mg^{2+})\) ions. These ions are responsible for the hardness of water. When water percolates through rocks and soil containing calcium and magnesium carbonates or sulfates, it dissolves these minerals, resulting in hard water. 

Option 1 (sodium and manganese) and option 2 (sodium and magnesium) are incorrect because sodium is not a major contributor to water hardness. Option 4 (calcium and sodium) is also incorrect because sodium is not a component that contributes significantly to water hardness compared to calcium and magnesium.