Answer
Level 0: a;
level 1: b, c, d;
level 2: e through k (in alphabetical order);
level 3: l through r;
level 4: s, t ;
level 5: u
Work Step by Step
---The level of each vertex of the rooted tree in given is
--Level 0: a;
-- level 1: b, c, d;
-- level 2: e through k (in alphabetical order);
--level 3: l through r;
--level 4: s, t ;
-- level 5: u
