What trend doesMary Ellen Iskenderian discuss regarding Women's World Banking product innovations in the webinar "Microfinance: Meeting Needs with More than Just Loans"?

a.Mandatory health insurance for microloan clients have improved loan repayment

b.Automation of client payments allows for a better database to manage client risk

c.Using technology of voice messaging a client to go for a checkup improves health insurance outcomes

d.Commercial banks are interested in serving the poor but retreat when they realize it is costly and labor intensive