Answer: the answer is c.
Step-by-step explanation: Let W, L and D = the width, length and diagonal of the rectangle, respectively.
Then, by the Pythagorean theorem,
W^2 + L^2 = D^2
<=>
D = sqrt(W^2 + L^2)
= sqrt(90^2 + 200^2)
= sqrt(48100)
= 10 sqrt(481)
None of the choices offers an exact solution. However, an approximate solution is:
10 sqrt(481) ≈ 219.317,
which rounds to 219, so the closest answer is C.