the complete question in the attached figure
we have that
A door to a playhouse is 50 inches tall
we know that
1 in---------------> is 0.0833333 ft
so
50 in-------------> 50*0.0833333---------> 4.167 ft
4.167 ft----------> [4 ft+0.167 ft]
remember that
1 in---------------> is 0.0833333 ft
X in----------------> 0.167 ft
X=0.167/0.0833333----------> X=2 in
therefore
4.167 ft----------> [4 ft+0.167 ft]--------> [4 ft+2 in]
the answer is
the option b) 4 ft 2 in