According to the passage, the disappearance after 1993 of known evening bat roosts in buildings suggests which of the following? A. After 1993 evening bats in Indiana were less likely to live near rivers. B. Humans and their structures became increasingly threatening after 1993. C. The spillover of large bat populations from woods near rivers increased after 1993. D. Evening bats in Indiana inhabited the roosts previously used by big brown bats. E. In Indiana, evening bats' adaptation to buildings was ultimately undermined by other factors.