Explanation:
Panda (2011) targeted low-quality content.

ALSO KNOW (related points):
• Which Google update (2013) improved its understanding of conversational queries and meaning, rather than exact keywords? → Hummingbird
• Which Google update (2014) affected local search results? → Pigeon
• What is a featured snippet? → A highlighted answer box shown above or near the top of the organic results, sometimes called 'position zero'