Which type of signaling does Ultra2 SCSI and Wide Ultra2 SCSI use?

A.
High-Voltage Differential (HVD)

B.
Low-Voltage Differential (LVD)

C.
Differential (DIFF)

D.
Single-Ended (SE)

Explanation:
Wide Ultra2 SCSI, Ultra2 SCSI, Ultra160 SCSI, Ultra320 SCSI and Ultra640 SCSI use Low-Voltage Differential (LVD) signaling.
References:
Charles J. Brooks, Server+ Certification Exam Cram 2 (Exam SK0-002), QUE Publishing, Indianapolis, 2006, pp. 143-147.
Brad Hryhoruk, Diana Bartley, and Quentin Docter, Server+ Study Guide (2nd Edition), Sybex, Alameda, CA, 2002, pp. 119-120.