The question is incomplete. It says:

'A' and 'B' formed in the following set of reactions are:

but the actual reaction scheme/figure and the options are missing. The listed options appear only as placeholders:

• A:
• B:
• C:
• D:

So there is not enough chemical information to determine what compounds 'A' and 'B' are.

Why the answer cannot be derived

To solve such an organic chemistry question, I would need:

1. The starting compound,
2. The reagents/conditions in each step,
3. The structures or names of the four options.

Without these, no valid step-by-step chemical deduction can be made.

Comparison with stored correct answer

The stored correct answer is given as C, but since the reaction sequence and options are absent, I cannot independently verify whether C is correct.

Hence, the proper conclusion is that the problem statement is incomplete and unsolvable as provided.