The C# team posts answers to common questions and describes new language features
Alexandru Ghiondea from the C# team created an excellent deck of slides that he used at Microsoft Days 2010 in Bulgaria. The C# team reused the deck several times for User Groups' presentations and talks. If you are planning a talk at your User Group, feel free to download. And even if you are not, it’s still might be useful to take a look – it’s a nice overview of the new C# 4.0 and Visual Studio 2010 features.
There are three presentations included: Introduction to C# 4.0, Increased Productivity with Visual C# IDE, and Dynamic Deep Dive.
Sorry for the previous comment, my bad, the correct answer is (b) only, as the location of the arguments are interchanged. Input will go as x:4 y:5 to base.foo then it will be transfered to derived as y:4, x:5 'coz the order is changed. then it will pring x:5, y:4 (b)