The question is not complete because it does not show the options, however, the problem can still be solved and serve as a teaching for the student.
see the picture attached to better understand the problem
we know that
in a right triangle ABC
tan 15°=opposite side angle 15°/ adjacent side angle 15°
where
opposite side angle 15°= h (the height of the building)
adjacent side angle 15°=550 ft
so
tan 15°=h/550-----------> h=550*tan 15°----> h=147.37 ft
the answer is
the height of the building is 147.37 ft (round to the nearest hundredth)
and
the expression to calculate the height of the building is
550*tan 15°