Mohit remembers that his niece Trishu had certainly been in Pune for one day after 16th February but before 21st February. While Mohit's mother remembers that Trishu had certainly visited Pune before 20th February but after 17th February. If both of them are correct, then on which day in February had Trishu visited Pune? (SOF NCO 2016)

• A. 18th                             
• B. 19th                              
• C. Either 18th or 19th                   
• D. 20th