Metrology is the study of 

The correct answer is  the measurement and arrangement of coins by weight.Key Points 

• Metrology is the study of measurement, including the development of measurement standards and methods.
• It covers a wide range of topics, including dimensional metrology (the measurement of length, width, height, and other dimensions), mass metrology (the measurement of mass), temperature metrology (the measurement of temperature), and time and frequency metrology (the measurement of time and frequency).
• While coin metrology (the study of coins and their properties, including weight and size) is a subfield of metrology.

• Coin metrology is a small part of the larger field of metrology and focuses specifically on coins as a type of measurement standard.

Hence the correct answer is option (3).Additional Information Chronology of coins

• The study of the chronology of coins is called Numismatics.
• Numismatics is a branch of archaeology and history that focuses specifically on the study of coins, tokens, medals, and other forms of currency.

The study of weather

• The study of weather is called Meteorology.
• Meteorology is a branch of atmospheric science that deals with the study of the atmosphere and its processes, including the physics, chemistry, and dynamics of the atmosphere and how it affects our weather and climate.

The study of metals

• The study of metals is called Metallurgy.
• Metallurgy is a branch of materials science and engineering that deals with the extraction, processing, and fabrication of metals and alloys.
• It involves the study of the physical and chemical properties of metals and alloys, as well as the development of methods for refining, purifying, and forming metals into useful products.