The dividing meridian between zone descriptions -7 and -8 is __________.

Correct Answer: Option A — 112°30'E

Zone description -7 is centered on 105 degrees East, and Zone -8 is centered on 120 degrees East. The exact dividing meridian separating these two easterly time zones lies halfway between them at 112 degrees 30 minutes East, following standard maritime navigational time zone boundaries.