The dividing meridian between zone descriptions -4 and -5 is __________.

Correct Answer: Option C — 67°30'E

Standard time zone boundaries span $15^{\circ}$ of longitude centered on meridians that are multiples of $15^{\circ}$. The dividing meridian between zone $-4$ ($60^{\circ}\text{E}$) and zone $-5$ ($75^{\circ}\text{E}$) lies exactly halfway at $67^{\circ}30'\text{E}$.