Answer
B
Work Step by Step
Number of moles of permanganate:
$34.50\ mL\times 0.108\ M=3.73\ mmol$
From stoichiometry: $9.32\ mmol$ oxalic acid.
Number of moles, if A:
$1.356\ g/305.00\ g/mol=4.45\ mmol$
Ratio: $9.32/4.45=2.09$
Number of moles, if B:
$1.356\ g/437.20\ g/mol=3.10\ mmol$
Ratio: $9.32/3.10=3.00$
Since in B the ratio of oxalates is closer to the stoichiometric ratio in the compound, it's B.
