Explanation:

Correct Answer is (d).‘The alternative’ is the subject for the verb 'appear' and since the subject is singular in form the verb must be 'appears' instead of 'appear'.
Besides, ‘superior’ or ‘inferior’ has the force of comparative degree and is followed by ‘to’ and not ‘than’. When two adjectives require different prepositions, appropriate prepositions should be used with both adjectives. e.g.,
Ex. He is senior and older than I. (Use ‘to’ after ‘senior’)
Ex. His dress is different and cheaper than mine. (Use ‘from’ after ‘different’)
Ex. She is stronger and younger than her sister. (Correct)
Hence, the option D is correct.