Kaplan kit

Hello tutor, Compared to ordinary secured loan notes, which of the following statements is true when considering convertible secured loan notes? A Likely to be more expensive to service because of their equity component B Likely to be less expensive to service because of their equity component C Likely to be more expensive to service because converting to equity requires he holders to make additional payments D Likely to be less expensive to service because they must rank after ordinary secured loan stock Answer is B What "expensive to service" means? Is it interest rate?