Which of the following is not a passive activity? A. A trade or business in which the taxpayer participated for 400 hours during year, B. A working interest in an oil or gas property, so long as the interest holders' liability is not 5. limited under state law. C. A rental activity, regardless of material participation. A trade or business for which the taxpayer participates 150 hours during the year, but less D. hours than employees of the activity