Final answer:
The correct sequence using the comparative form of 'bad' is 'bad - worse - the worst'. 'Worse' is the comparative form, while 'the worst' is the superlative form. The correct answer is 2.
Step-by-step explanation:
The correct comparative form of 'bad' is 'worse,' not 'badder' or 'bader.' Therefore, the correct sequence is bad - worse - the worst. The word 'bad' is an irregular adjective, which means its comparative and superlative forms do not follow the regular pattern of adding '-er' or '-est' to the base adjective.
Instead, 'bad' changes to 'worse' when comparing two things, and 'the worst' when comparing three or more things. Hence the correct option is 2.