You need to improve the performance of the application

You are developing an application that uses many small images.
When the images load, the application runs slowly.
You need to improve the performance of the application.
What should you do?

A.
Preload all the images when the application starts to ensure that the images are cached.

B.
Convert the images to ICO file format and stream all images on a single connection.

C.
Host all images on a Microsoft Azure web role with multiple instances.

D.
Combine all the images into a single image and use CSS to create sprites.

Explanation:
Because browsers limit how many concurrent HTTP requests they make to a website, a web page
with many small icon images can result in a longer load time. You can combine many small images
into a single larger image ‐ a CSS sprite ‐ using the free ASP.NET Sprite and Image Optimization
Library available from Microsoft.
CSS Sprites and the ASP.NET Sprite and Image Optimization Library
http://dotnetslackers.com/articles/aspnet/CSS‐Sprites‐and‐the‐ASP‐NET‐Sprite‐and‐Image‐
Optimization‐Library.aspx