Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: Houston (CNN) -- Aviation fans have already named it Dreamliner 2.0. No longer grounded for safety concerns, Boeing's embattled 787 Dreamliner now has a few things to prove. Monday might be a good day to start. That's when domestic Dreamliner flights return to America's airways. At 11 a.m., United Flight 1 is scheduled to depart Houston's George Bush Intercontinental Airport for Chicago's O'Hare International Airport. The airline plans to roll out additional 787 flights throughout the week. Some international carriers have already resumed Dreamliner service. For aviation enthusiasts it's kind of a big deal. As word spreads of Dreamliner's return, travel advisers report they're getting calls from curious fliers looking to connect with one of United's six 787s at Dreamliner hubs.United Flight 1 is the first U.S. commercial Dreamliner flight in more than four monthsBattery troubles led the FAA to ground the 787, the first model fleet grounded in 30 yearsExperts say plane is safe; travel advisers say enthusiasts are requesting bookingsIt's the first of a new generation of efficient airliners that can carry 200-plus passengers 
 Question:Most aren't worried about flying the 787, but if _ develops another problem "then that might change things."

787 Dreamliner