Which of the following calculations would result in a final answer with 4 significant figures:                             A.    25.45 grams plus 2.37 grams                               B.   45.00 grams divided by 20.2 mL                                C.  125.5 mL minus 5.4 mL

The answer is B. 45.00 grams divided by 20.2 mL.

Here's the step-by-step explanation:

A. 25.45 grams plus 2.37 grams = 27.82 grams. This result has four numbers but only three of them are significant figures because the leading zero is not considered a significant figure.

B. 45.00 grams divided by 20.2 mL = 2.2277 grams/mL. This result has five numbers but we can round it to four significant figures, which is 2.228 grams/mL.

C. 125.5 mL minus 5.4 mL = 120.1 mL. This result has four numbers but only three of them are significant figures because the leading zero is not considered a significant figure.

Therefore, only option B would result in a final answer with 4 significant figures.