Wnat is an average profit margin in an industry?

a$.$ The ratio of a company's human resource assets over its strategy expenditures averaged across all companies in an industry

b$.$ The ratio of a company's strategic deficits over its operations expenditures averaged across all companies in an industry

c$.$ The ratio of a company's distributional deficits over its costed expenditures averaged across all companies in an industry

d$.$ The ratio of a company's profit $($sales minus all expenses$)$ divided by its revenue averaged across all companies in an industry

e$.$ The ratio of a company's supply chain deficits over its marketing expenditures averaged across all companies in an industry