This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
As you can see here there will be an compile time error based on incompatible referencing,and this was the probable answer given in Jxam.And this was the only one given by them. But they have missed one that is also correct. ie. The program will compile if the first line is altered to String s = new String("abcd");