Smith in Evaluating Issuance Costs from Underwritten Issues, Rights Issues

Smith in evaluating issuance costs from underwritten issues, rights issues with standby underwriting and a pure rights issues found that 90 percent of the issues are underwritten which was the most expensive method. This is done because:

A) investment bankers know more than CFOs and they may buy the issue at an agreed price and disburse the funds sooner.
B) investment bankers can increase the price received by increasing confidence in the issue, they will buy the issue at an agreed upon price and disburse the cash sooner.
C) investment bankers provide other services including price counsel, increase public confidence and provide funds to the issuer sooner.
D) investment bankers know how to price the issue, would not need to set as low as a price as the subscription price and provide price counsel.