Passage Summary: The global cow population is rising and releasing methane; since better food makes cows less gassy, switching their feed could help limit total methane levels.

Conclusion: Methane production from cows could be controlled by providing them with higher-quality diets.

Reasoning: Cows produce less methane when fed better diets, and currently, the majority of the world's growing cow population is fed low-quality diets.

Analysis: The argument assumes that the reduction in methane per cow would be significant enough to offset the overall increase in the number of cows. To strengthen this, we need to bridge the gap between 'individual cows produce less' and 'total methane is kept in check.' Look for an answer that suggests the dietary improvement has a substantial impact or that the population growth won't completely negate the benefits of the better feed.