Answer : Option B) 360 g/mol
Explanation : The antibacterial agent Penicillin N contains 8.92% of sulfur by mass. So we have to calculate the molar mass of penicillin N will be as
i) 256 X 0.0892 = 22.83 g/mol this cannot be the answer as it doesn't shows any sign of sulfur being present even in 1 mole.
ii) 360 X 0.0892 = 32.112 g/mol This is the closest to the molar mass of sulfur which is 32.06 g/mol; this means it contains 1 mole of sulfur.
iii) 390 X 0.0892 = 34.78 g/mol this also fails to prove the answer as correct.
iv) 743 X 0.0892 = 66.27 g/mol This is not even falling in the range of sulfur mole.
Hence we can confirm that the answer is Option B