Option D, 5 and 6
In order to estimate what the cube root of 200 is, we can simply cube root the options and check if they're near 200.
Option A: 66*66, as you can tell, is way way bigger than 200, so we can scratch that off without having to do any calculations.
Option B: The same goes for Option B. 20*20 is already twice the size of 200, and so we can scratch this one off too.
Option C: 6 and 7? Seems pretty close. Let's give it a shot.
= 216. Whoops, guess not. The smaller number should be smaller than 200, and the bigger number should be larger than 200.
Option D: Seeing that all the other options were wrong, it looks like D is our only answer. 5*5*5 = 125, and 6*6*6 = 216. Since 125 is less than 200 and 216 is greater, we can confirm that Option D is the right answer
If there's any part that needs clarification, just tell me and I'll explain it.
Good luck! :)
-T.B.