To find the best estimate for 161.75, we can round it to the nearest whole number. The value 161.75 is closest to 160, which is halfway between 128 and 196. However, rounding to the nearest significant number from the options given:
- 256 is too high.
- 196 is relatively close and is a common rounding number.
- 128 is somewhat lower.
Among the given options, 196 is the best estimate for 161.75.