The correct answer is option 'C': Nanometer is a unit for measuring micro-distance.

Explanation:

► What is a nanometer?
A nanometer (nm) is a unit of length in the metric system. It is equal to one billionth of a meter, which means it is extremely small. To put it into perspective, a nanometer is about 100,000 times smaller than the width of a human hair.

► Measuring micro-distance:
When we talk about measuring micro-distances, we are referring to distances that are on the scale of millionths of a meter. These distances are so small that they cannot be accurately measured using traditional measuring instruments like rulers or tape measures. Instead, specialized instruments are needed, and one of the units used to represent these small distances is the nanometer.

► The nanometer as a unit of measurement:
The nanometer is commonly used in various scientific fields, particularly in nanotechnology, physics, and chemistry. It allows scientists to measure and describe the size of particles, wavelengths of light, and the dimensions of structures at the nanoscale.

► Examples of nanoscale objects:
- A single molecule can have a size on the order of a few nanometers.
- The diameter of a typical virus particle ranges from 20 to 300 nanometers.
- The thickness of a human hair is about 80,000 to 100,000 nanometers.

► Importance of nanoscale measurements:
Understanding and manipulating objects at the nanoscale is crucial for advancements in fields such as electronics, materials science, medicine, and energy. Many modern technologies, including computer chips, solar cells, and medical devices, rely on nanoscale structures and precise measurements.

► Conclusion:
In conclusion, a nanometer is a unit for measuring micro-distances. It represents a length that is extremely small and is commonly used in scientific research and technological advancements. By using nanoscale measurements, scientists can better understand and manipulate the world at the atomic and molecular level.