Jan has two children and four grandchildren. She inherited an estate from her husband worth $25 million and began making gifts to reduce her estate. This year she made the following transfers and has allocated her GST exemption to all of them: 1. She created an irrevocable trust funded with $5 million that provides her children with income for life. The corpus will be distributed to her grandchildren at the last child's death. 2. She gave her children, grandchildren, and two great nephews $20,000 for their birthdays this year. 3. She established separate irrevocable trusts for each of her grandchildren, which she funded with $500,000. The income in these trusts will accumulate untli each child attains age 35 . How much of Jan's GST exemption remains to offset taxes on future gifts? a. $4,000,000 b. $4,020,000 c. $4,150,000 d. $5,890,000