A metre long narrow bore held horizontally (and close at one end) contains a `76` cm long mercury thread, which traps a `15` cm column of air. What happens if the tube is held vertically with the open end at the bottom?

Options

A. 23.8 cm of mercury flows out
B. 27.8 cm of mercury flows out
C. 32.8 cm of mercury flows out
D. None of these