Sandra sold shares of Wren Corporation to Bob, her brother. She had paid $20,000 for the stock. Calculate Sandra's and Bob's realized and recognized gain or loss under the following circumstances.

(a) Sandra sold the shares to Bob for $17,000.

(b) Bob later sold those shares in a. for $25,000.

(c) Sandra sold the shares to Bob for $18,000.

(d) Bob sold those shares in c. for $19,000.