Which of the following system bus architectures operates at 66 MHz and has a throughput of approximately 528 MBps?

A.
32-bit PCI

B.
PCI-X

C.
AGPx1

D.
AGPx2

Explanation:
AGP operates at a clock speed of 66 MHz. The original AGP specification; sometimes referred to as AGPx1 had a data transfer rate of 264 MBps. AGPx2 has a transfer rate of 528 MBps, or twice the transfer rate of AGPx1.
Incorrect Answers:

A: PCI operates at a clock speed of 33 MHz. The 32-bit version of the PCI specification has a data transfer rate of 132 MBps.
B: PCI-X operates at a clock speed of 133 MHz.
C: AGP operates at a clock speed of 66 MHz. The original AGP specification; sometimes referred to as AGPx1 had a data transfer rate of 264 MBps.
References:
Gary Govanus, William Heldman and Jarret Buse, Server + Study Guide, Sybex, Alameda, CA, 2001, pp. 180, 192-193.
Charles J. Brooks, Server+ Certification Exam Cram 2 (Exam SK0-002), QUE Publishing, Indianapolis, 2006, pp. 107-108, 111-112, 114-117.