What is the relationship between 'DFS' and 'furniture' in the context of the input sentence.
Options: director/manager, product/material produced, owned by, position held

2015 has been a positive year thus far for investors in potash exploration company Sirius Minerals (LSE: SXX), support services contractor Balfour Beatty (LSE: BBY) and furniture seller DFS (LSE: DFS).
product/material produced