Minerals, organic matter, water and air.
“Total cost of all factors of production consumed or used in producing a good or service. ... Market price: Market price is the price at which a product is sold in the market. It includes the cost of production in the form of wages, rent, interest, input prices, profit etc”
Explanation:
At the center its weight is zero. Or you can argue by symmetry: if the weight is not zero, in what direction would it act?
