Refer to the input text as context and select the correct relationship between 'Lehman Brothers' and 'investment' from the available options.
Options: member of, operator, industry, director/manager

The civil charges against the veteran money manager, his son and their investment company come eight months after the Reserve Primary Fund, loaded with Lehman Brothers debt, halted redemptions after the investment bank declared bankruptcy, sparking a run on money-market funds.
industry