Which of the following is a key factor in determining how often someone should tan?

Skin type is indeed a crucial factor in determining how often someone should tan. Different skin types have varying levels of sensitivity to ultraviolet (UV) rays, which can affect how often an individual should engage in tanning sessions. For example, individuals with lighter skin types may burn more easily and thus require more caution and potentially less frequent tanning sessions to prevent overexposure and skin damage. In contrast, those with darker skin types may have a higher tolerance to UV exposure and might be able to tan more frequently.

Other factors like the location of the tanning center, cost of tanning sessions, and time of year can influence a person's tanning habits and decisions, but they do not directly impact the physiological responses of the skin to UV exposure. Understanding skin types helps tanning consultants offer personalized recommendations that prioritize the clients’ safety and skin health.