The given mass is 0.025563 g.
Examine the given choices.
a. 0.026 g
This uses 2 significant digits, with rounding to the 3rd decimal place.
b. 2.5 x 10² g = 250 g.
It is incorrect.
c. 0.025 g.
This uses 2 significant digits. It is inaccurate because it does not use rounding to the 3rd decimal place.
d. 0.02 g
This uses one significant digit. It is incorrect for representing the given data.
Answer: a. 0.026 g