Question: Which way are arrows supposed to point on a tabbed web page? Towards the selection or towards the body of the selection? An awkward scenario seems to arise when a user selects another item and the arrow moves to point at nothing in particular when the arrow is pointing to the body. Is there a best practice? 

![enter image description here](https://i.stack.imgur.com/WgSMw.jpg)

Answer: 
They both look wrong and unecessary. For a tabbed interface the colour of the tab should be the colour of the selected page.
One interpretation of the arrow up in your rendering (alternative B) is that the body of the text is like a speech-bubble. This makes it look like it comes from the header, which feels more natural than an arrow in my opinion. But as many have said, it is probably better to give the tab the same color as the content in that case.