Which of the following losses is excluded by the pollution liability exclusion of a commercial general liability policy?

a. A contractor stores several drums of chemical solvents on a work site. One of the drums leaks and damages water pipes on an adjacent property.
b. Fuel leaks from the gas tank of a grader when its gas tank is accidentally punctured.
c. Fumes escape from a hostile fire unrelated to remedial operations.
d. Tar that was used on a completed roof is accidentally ignited, releasing fumes in the neighborhood where the work was done. Several residents are injured.