Answer:
Option A.
Explanation:
The given expression is

We need to find the difference round to the less precise measurement.
Taking out the common factor.


Precise measurement of given expression is 81.2g.
A measurement with more decimal places is more precise and vice versa.
Now, approx the answer to the the nearest whole measure.

The less precise measurement of given expression is 81g.
Therefore, the correct option is A.