Long-term trends for private employer-sponsored insurance indicate that: A. the continued popularity of the preferred provider organization is reflected by the fact that it is still the fastest growing form of insurance. B. there is a resurgence in the popularity of traditional indemnity insurance coverage. C. the high-deductible health plan (HDHP) is now the most popular form of insurance for private sector employees covered by group plans. D. almost one-third of private sector employees covered by group plans are enrolled in some form of high-deductible health plan. E. enrollment in the staff-model health maintenance organization is becoming more popular