In: Economics
Capital goods are those goods which are durable and can last for many periods of production. They are not used up in one period of their use. They can be used in many production periods.
Material inputs on the other hand are those goods which are not durable and which are used up(finished) in the process of production in the the period in which they are used.
Capital goods do not become physically part of the output produced. It is the materials which become part of the output produced physically. Thus, Option B is Incorrect.
Moreover capital goods are not machinery only. Many Other goods can also be called capital goods such as building etc. Option C is incorrect
This is also not true that capital goods are bought on credit and materials are paid for in cash. Materials can also be bought for credit. Thus, Option D is incorrect.
show the main difference between capital goods and material inputs is that capital goods are durable ; materials are used up.
Therefore, Option A is correct.