Which of the following can cause a bottleneck?

A.
Faulty hardware that cause too much interrupts

B.
IRQ conflicts between hardware devices

C.
CPU-intensive applications

D.
Memory problems

E.
All of the above

Explanation:
Bottlenecks include CPU-intensive applications, processes, drivers, and interrupts. Faulty hardware can cause excessive interrupts, as can IRQ conflicts between hardware devices. In addition, memory problems have a tricky way of hiding behind high processor use.
References:
Charles J. Brooks, Server+ Certification Exam Cram 2 (Exam SK0-002), QUE Publishing, Indianapolis, 2006, p. 335