Glencore (Xetra: A1JAGV - news ) and Anglo American (LSE: AAL.L - news ) were the top fallers after Investec (LSE: INVP.L - news ) said the challenging environment for the sector calls into question the equity value of the mining companies.
Take context from the input text and decide on the accurate relationship between 'Glencore' and 'mining' from the options provided.
Options: subsidiary, industry, business division, founded by