$$A$$ and $$B$$ formed in the following reactions are:
$$CrO_2Cl_2 + 4NaOH \rightarrow A + 2NaCl + 2H_2O$$
$$A + 2HCl + 2H_2O_2 \rightarrow B + 3H_2O$$

A

$$A = Na_2CrO_4$$, $$B = CrO_5$$

B

$$A = Na_2Cr_2O_4$$, $$B = CrO_4$$

C

$$A = Na_2Cr_2O_7$$, $$B = CrO_3$$

D

$$A = Na_2Cr_2O_7$$, $$B = CrO_5$$