Answer:
See explanation
Step-by-step explanation:
According to Bronsted-Lowry definition of acids/bases, an acid is a proton donor while a base is a proton acceptor.
Hence, in a reaction, the species that donate protons are strong acids while the species that accept protons are strong bases.
Hence, HSO4- is a stronger acid than H2C2O4 and SO42- is a weaker base than HC2O4-
Note that the conjugate base of a strong acid is a weak base and vice versa.