I believe it’s C.) Mass. Hope I’m right.
Answer:
32.23 to 4 significant figures.
Explanation:
The molar mass of the element is the mass of 6.022 * 10^23 atoms (Avogadro's number).
So by proportion it is 6.022 * 10^23 * 3.88 / 7.25 * 10^22
= 32.23 to 4 significant figures.
Answer : 50.69 mg of ascorbic acid does not meet the daily requirement.
Solution : Given,
Molar mass of Ascorbic acid = 176 g/mole
Moles of Ascorbic acid = 
Formula used :

or, 
Now put all the given values in this formula, we get the mass of ascorbic acid.

Conversion : 
As per question, a healthy adult’s daily requirement of vitamin C is 70-90 mg. But calculate mass of vitamin C is 50.69 mg. So, 50.69 mg of ascorbic acid does not meet the daily requirement.