Utilize the input text as a context reference, choose the right relationship between 'Energy company' and 'natural gas' from the options.
Options: business division, stock exchange, product/material produced, operator

Energy company BG Group (LSE: BG.L - news ) has started up and loaded its first liquefied natural gas from the second production train at the Queensland Curtis LNG (QCLNG) facility in Australia.
product/material produced