An ISR be written to execute quickly because ________.

a) there can be several devices that interrupt at the same DIRQL, so returning quickly allows the system to determine which device is interrupting and service the interrupt faster.
b) the kernel interrupt handler holds the driver's spin lock while the ISR is executing, preventing other processors from executing some portions of the driver's code, including the ISR.
c) while the ISR is executing, the processor executes at the device's DIRQL, which might mask interrupts from other devices. Returning from the ISR quickly allows the system to maintain high responsiveness to all hardware interrupts.
d) all of the above

d) all of the above