Let Alice, Bob, and Darth be three non$-$root users of a UNIX system. Alice owns a directory D with permissions set to $1777($in numeric mode$).$ Bob has created a file F that is in directory D$.$ At some point, Bob decides to set permissions for F to $777($in numeric mode$).$ Darth, who wants to cause harm to Bob, decides to take advantage of the latter and attempts to delete file F$.$ Can Darth succeed in his attempt? Justify your answer.