Glencore (GLEN.L) slumped more than 15 percent to a new all-time low after a bearish note from broker Investec that raised doubts over the mining and commodities company's valuation and high debt levels.
Utilize the input text as a context reference, choose the right relationship between 'Glencore' and 'mining' from the options.
Options: industry, parent organization, owned by, stock exchange