To solve this question, the user needs to have knowledge about QTP and its various types of checkpoints. The user needs to know the purpose of each checkpoint and how they are used to test web pages.

Now, let's go through each option and explain why it is right or wrong:

A. Bitmap checkpoint: This checkpoint compares the bitmap of the actual and expected images, so it is used to verify the graphical elements of the web page. It is not used for verifying the web page with the W3C standard.

B. Standard checkpoint: This checkpoint verifies the property values of an object on a web page. It can be used to check the compliance of the web page with W3C standards, but it is not specifically designed for this purpose.

C. Accessibility checkpoint: This checkpoint is used to verify the accessibility of a web page for users with disabilities. It includes checking the compliance of the web page with W3C accessibility guidelines, which are related to W3C standards. So, this checkpoint is the correct option for verifying the web page with W3C standard.

D. XML checkpoint: This checkpoint verifies the content of an XML document. It is not used for verifying the web page with W3C standard.

The Answer is: C (Accessibility checkpoint)