This is the only compound I found that matches the description.
To compute for the empirical formula, assume there is 100 grams of the compound. That means there is 40.28 g B, 52.2 g N and 7.53 g H. Convert the mass into moles using their molar masses:
40.28 g B * 1 mol/10.811 g = 3.725835 mol B
52.2 g N * 1 mol/14 g = 3.72857 mol N
7.53 g H * 1 mol/1 g = 7.53 mol H
Divide all the moles by the smallest amount which is 3.725835 mol.
B: 3.725835/3.725835 = 1
N: 3.72857/3.725835 = 1
H: 7.53/3.725835 = 2
Therefore, the empirical formula is BNH₂.
Answer : Option C) 0.3 mol of Gold.
Explanation : Amongst the options given in the question, 0.3 mol of Au is the greatest in mass in grams.
As 0.3 mol X atomic weight of Au (196.966) = 59.088 grams;
Silver has 0.5 mol X atomic weight of Ag (107.86) = 53.93 grams;
The other options are not relevant as they deal in the atomic range which has mass value very less as compared to the moles of elements.
Therefore, it is clear that Au has the greatest mass amongst the given choices.