Select the correct answer.
Which mathematical relationship should you use to convert moles of a substance into grams?
 A. 
mass in grams = number of moles · molar mass in g/mol
 B. 
`"mass in grams" = ("number of moles")/ ("molar mass in g/mol")`
 C. 
`"mass in grams" = ("molar mass in g/mol")/ ("number of moles")`
 D. 
mass in grams = molecular weight · molar mass in g/mol