What is the relationship between impact and CD in the context of the input sentence. Choose an answer from: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

The second quarter increase was driven by a decrease in the interest expense due to a combination of lower rates, lower brokered CD balances and a decrease in the impact of the accelerated premium expense associated with calling the remaining brokered certificates of deposits.

Answer: distribution_format