At the command prompt, type cd b and press Tab. Did the display change?

$6$

Press the Tab key again. How many subdirectories under the root begin with $$b$?$

$7$

Type the letter i$.$ Notice that the command now reads $$cd bi$.$ Press the Tab key again. Which directory did it expand to$?$ Why? Press the Ctrl$+$c keys to cancel the command and return to an empty command prompt.