The correct answer is D. Cdma2000.
Cdma2000 is a family of 3G digital cellular radio technologies that evolved from the second-generation IS-95 CDMA standard. It is a direct-sequence spread spectrum (DSSS) technology that uses a spread spectrum modulation technique to spread the transmitted signal over a wide bandwidth. This makes it more resistant to interference and allows for multiple users to share the same frequency band.
Cdma2000 is a wideband CDMA (WCDMA) technology, which means that it uses a wider bandwidth than narrowband CDMA technologies like IS-95. This allows for higher data rates and better performance.
Cdma2000 is also a multicarrier technology, which means that it uses multiple carriers to transmit data. This allows for higher capacity and better performance in areas with high traffic.
Cdma2000 is a mature and widely deployed technology. It is used by many operators around the world, including Verizon Wireless, Sprint, and AT&T.
A. IS-95 is a second-generation digital cellular radio technology. It is a narrowband CDMA technology that uses a narrower bandwidth than Cdma2000. This means that it has lower data rates and worse performance than Cdma2000.
B. IS-95B is an enhanced version of IS-95. It offers higher data rates and better performance than IS-95. However, it is still a narrowband CDMA technology and is not as capable as Cdma2000.
C. CdmaOne is a generic term for all CDMA technologies. It includes IS-95, IS-95B, and Cdma2000.
Therefore, the correct answer is D. Cdma2000.