Basis on Sale of Gifted Stock

Tom gave his son, David, a birthday present of Big M stock with a fair market value of $50,000. Tom paid gift tax of $9,700 as Tom had previously given David earlier this year a cash gift. Tom’s adjusted basis in the stock on the date of the gift was $30,000. Three months later, David sold the stock for $75,000. What was David’s basis on the date of sale of the stock?
- $20,000
- $27,020
- $31,700
- $50,000