Question

I'm not sure if D is right

Answer 1

Ratio and proportion

height :legnth of shadow=56:49 (man's shadow)
we assume the ratio is the same for the tower thing (obelisk)

so
56:49=x:28
conver tto fraction
56/49=x/28
times both sides by 28
1568/49=x
32=x
answer is 32ft