Analyze the relationship between 'Lehman Brothers' and 'investment bank' within the context of the input sentence.
Options: product/material produced, developer, legal form, owned by

Another answer lies in shifting investor expectations of market shocks, five years after the U.S. "flash crash" that briefly wiped out nearly $1 trillion in market value and seven years after the subprime crisis pushed investment bank Lehman Brothers into bankruptcy and redrew the financial landscape.
product/material produced