In the context of the input sentence, determine the relationship between 'Sony' and 'software'.
Options: chief executive officer, stock exchange, product/material produced, headquarters location

Microsoft ( MSFT.O ) added 1.2 percent to $20.76 after the software maker said it sold 28 million units worldwide of its Xbox 360 video game console through the end of 2008, extending the Xbox's lead over rival Sony Corp's ( 6758.T )( SNE.N ) PlayStation 3.
product/material produced