In Microsoft Silverlight, what is a key difference between Silverlight 1 0 and Silverlight 2 from a development perspective?

Introduction / Context:
Silverlight evolved quickly in its early versions. Silverlight 1 0 offered rich media and graphics but relied on JavaScript for application logic. Silverlight 2 introduced a significantly more powerful programming model by adding a subset of the NET Common Language Runtime. This change allowed developers to use managed languages and a rich set of controls. This question checks whether you know that the shift from pure JavaScript to managed NET code was the major development difference between version 1 0 and version 2.

Given Data / Assumptions:

• Silverlight 1 0 applications defined user interface mainly in XAML and used JavaScript for logic.
• Silverlight 2 introduced the NET CLR inside the plug in.
• Managed languages such as C sharp became available with Silverlight 2.
• The focus is on the programming model, not minor feature additions.

Concept / Approach:
Silverlight 1 0 was essentially a rich browser plug in that combined XAML based vector graphics and media support with JavaScript integration. All application logic had to be written in JavaScript and ran in the browser script engine. Silverlight 2 extended the platform by embedding a reduced NET CLR into the plug in. This enabled developers to write code in C sharp or Visual Basic, use a comprehensive set of controls, benefit from a powerful base class library, and build XAML based user interfaces similar to WPF. The introduction of managed code and controls is the main difference highlighted in official documentation and interview guidance.

Step-by-Step Solution:
Step 1: Recall that Silverlight 1 0 logic was written in JavaScript and that no managed NET CLR was available. Step 2: Remember that Silverlight 2 introduced the CLR, enabling managed code and richer control sets. Step 3: Compare options and select the one that clearly contrasts JavaScript based logic in 1 0 with NET based logic in 2. Step 4: Option A exactly states that Silverlight 1 0 relied on JavaScript, while Silverlight 2 added the NET CLR, managed code, and controls.

Verification / Alternative check:
You can verify by considering development tools. Early Silverlight 1 0 projects were often authored with XAML and JavaScript using basic tools or plug ins. With Silverlight 2, Visual Studio templates supported managed code behind files, data binding, and richer control libraries. This change in development workflow reflects the introduction of the NET CLR and confirms option A as the correct description.

Why Other Options Are Wrong:
Option B is the exact opposite of what happened; managed code was introduced, not removed, in Silverlight 2. Option C is wrong because both versions targeted desktop browsers rather than focusing only on mobile. Option D is incorrect because Silverlight 2 maintained and extended media capabilities. Option E is wrong because the programming model changed significantly between 1 0 and 2, particularly through the addition of the CLR and managed code support.

Common Pitfalls:
A common pitfall is to treat all Silverlight versions as the same from a development perspective and ignore the major runtime change in version 2. Another mistake is to focus only on visual changes and overlook the underlying shift to managed languages. Understanding that Silverlight 2 introduced the CLR, managed code, and a richer control library is essential for answering historical technology questions accurately.

Final Answer:
Silverlight 1 0 relied on JavaScript for application logic, while Silverlight 2 introduced the NET CLR with managed code, controls, and XAML based applications