What is the relationship between 'Plug Power' and 'fuel cell' in the context of the input sentence.
Options: distribution format, legal form, product/material produced, parent organization

Following the Feb 2014 announcement that Plug Power will supply 1,738 GenDrive fuel cell units to Wal-Mart’s six North America distribution centers over the next two years, its shares catapulted 133.8% till almost mid March.
product/material produced