The correct answer is D. diminution.
The property of contraction of matter on cooling is put to several practical uses. For example, it is used in the manufacture of glass, which is made by heating sand until it melts and then cooling it slowly. The contraction of the glass as it cools causes it to become denser and stronger. This is why glass is such a versatile material that can be used for a variety of purposes, from windows and bottles to lenses and mirrors.
The other options are incorrect because they do not accurately describe the property of contraction of matter on cooling. Option A, improvement, is incorrect because contraction is not necessarily an improvement. In some cases, it can be a disadvantage. For example, if a metal contracts too much when it cools, it can become brittle and break. Option B, growth, is incorrect because contraction is the opposite of growth. Option C, expansion, is incorrect because contraction is the opposite of expansion.