$39.$ Which of the following is a circumstance under which an "unintentional failure to disclose hazards" endorsement would preserve coverage?

$($Search Chapter $10)$

a$.$ Fred's Fine Floors fails to inform a customer that the chemicals it will use to strip the finish off hardwood floors is hazardous.

b$.$ Zeus Custom Kitchens fails to tell a client of its intention to use a subcontractor to install his gas cooking appliances.

c$.$ Bob's Big Buildings neglects to mention in its application for insurance that it sometimes agrees to provide the design for a building as well as construct it$.$

d$.$ Franklin Real Estate Development intentionally conceals the fact that it has been fined by OSHA for unsafe working conditions three times in the past five years when applying for CGL insurance.