The correct answer is: B. External trap
An external trap is generated by an external event, such as a hardware interrupt. It is a type of exception that causes the processor to stop executing the current instruction and transfer control to a special routine called an interrupt service routine (ISR).
An internal trap is generated by a fault within the processor itself, such as an arithmetic overflow or division by zero. It is also a type of exception that causes the processor to stop executing the current instruction and transfer control to an ISR.
A memory trap is generated by a fault accessing memory, such as a page fault. It is also a type of exception that causes the processor to stop executing the current instruction and transfer control to an ISR.
An interfaced trap is a type of trap that is generated by an external device, such as a network card. It is also a type of exception that causes the processor to stop executing the current instruction and transfer control to an ISR.
In conclusion, an external trap is generated by an external event, such as a hardware interrupt. It is a type of exception that causes the processor to stop executing the current instruction and transfer control to a special routine called an interrupt service routine (ISR).