先发一个AI的summary。

At the April 2011 White House Correspondents' Dinner, President Obama famously roasted Donald Trump, mocking his role in "birther" conspiracy theories and his reality TV persona, NPR reports. Obama sarcastically praised Trump for focusing on, "did we fake the Moon landing?" after releasing his birth certificate, National Archives. 

Key details of the 2011 roast and remarks included:

• The "Birther" Mockery: Obama joked that Trump could finally move on to other serious issues like, "What really happened in Roswell?" and "Where are Biggie and Tupac?".
• "Celebrity Apprentice" Quips: Obama highlighted Trump’s decision-making by joking about him firing Gary Busey on Celebrity Apprentice, noting, "These are the kind of decisions that would keep me up at night".
• Visual Roast: The president showed a fake picture of the White House with a bikini-clad, hot-tub-focused redecoration to mock what a "Trump White House" might look like, BBC News reports.
• Motivation for a Run: PBS reports that advisers close to Trump, such as Roger Stone, believed this specific night of intense public humiliation was the turning point that motivated Trump to run for president, according to the documentary The Choice 2016. 

Trump was famously stony-faced during the roast, which took place just days after the Obama administration released his long-form birth certificate, BBC reports.