The correct answer to this question would be alternatives: A)"Natural Resources."; B)"Work Force." and C)"Capital."
It's of the utmost importance to have natural resources and qualified work force, to make sure that the capital invested to achieve growth in the industry results in good merchandise.
We can't put merchandise into account in this question because it's the final product, and not something that's within the industry.
Good People (Work Force), Good Materials (Natural Resources) and the right amount of investment (Capital) to make it all work together, are the basic requirements for industry growth.