What type of altitude is used to determine VFR cruising altitudes?

The correct answer is pressure altitude because VFR (Visual Flight Rules) cruising altitudes are determined based on pressure altitude, which is defined as the altitude in the standard atmosphere corresponding to a given atmospheric pressure. When flying under VFR, pilots must use pressure altitude to establish cruising altitudes above a specific minimum, which are segregated based on the compass heading (odd thousands feet for altitudes from 0 to 18,000 feet MSL when flying on a magnetic course of 0-179 degrees, and even thousands feet for 180-359 degrees).

Using pressure altitude ensures that pilots maintain proper vertical separation from one another and helps in standardizing altitude definitions regardless of the actual atmospheric conditions. In practice, this means that all pilots will reference the same, common altitudinal baseline for safety and coordination.