The correct answer is: A. Both A and R are true and R is the correct explanation of A.
Synthetic detergents are made up of long chains of molecules with a hydrophobic (water-hating) end and a hydrophilic (water-loving) end. The hydrophobic end of the molecule attaches to the dirt or grease, while the hydrophilic end attaches to the water. This allows the detergent to lift the dirt or grease away from the surface and suspend it in the water so that it can be rinsed away.
Hard water contains minerals such as calcium and magnesium. These minerals can form insoluble salts with the detergent, which can prevent the detergent from working properly. However, synthetic detergents are designed to form soluble salts with these minerals, which means that they can still lather well in hard water.
Therefore, both A and R are true, and R is the correct explanation of A.
Here is a more detailed explanation of each option:
- Option A: Both A and R are true and R is the correct explanation of A. This is the correct answer, as explained above.
- Option B: Both A and R are true, but R is not the correct explanation of A. This is not the correct answer, as R is the correct explanation of A.
- Option C: A is true, but R is false. This is not the correct answer, as R is true.
- Option D: A is false, but R is true. This is not the correct answer, as A is true.