Zeb plans to make a traditional IRA contribution for 2018. Which of the following situations allows Zeb to make a fully deductible contribution? O A. Zeb is self-employed and makes contributions to a Keogh plan. O B. Zeb makes deductible contributions to a Section 501(c) 18) trust. O C. Zeb participates in a qualified plan but does not vest for several years. O D. Zeb's spouse is an active participant in a SEP