Which of the following best describes the relationship between methane recapture systems and sustainable farming techniques?

Methane recapture systems do not qualify as a sustainable farming technique.
Methane recapture systems are one form of sustainable farming technique.
Methane recapture systems cause harm and create a need for sustainable farming techniques.
Methane recapture systems are an ancient form of sustainable farming technique.

The methane gas produced through anaerobic fermentation action in farm tank is recaptured, pumped and used for various purposes. Since the methane gas is trapped and used for other useful purposes and not allowed to escape into the atmosphere, methane recapture system does not contribute to climate change or global warming. Recaptured methane is used to:

Generate electricity to:

Supply power to units like greenhouses, animal houses, etc in the farm.
Heat and light up houses
Farm activities driven by power
Excess can be sold for profit to nearby power stations

The water is recycled for farming
The solid wastes are converted and used as manure

Hence methane recapture systems are one of the best sustainable farming methods

So this is a sustainable farming method .