Explanation:

“Eccentric” means (of a person or their behaviour) unconventional and slightly strange. Therefore, the set of words that reflect the synonyms of the given highlighted word is “Peculiar : Bizarre”. Hence, option (a) is the most suitable answer choice.
Peculiar means different to what is normal or expected; strange.
Bizarre means very strange or unusual.
Altruistic means showing a disinterested and selfless concern for the well-being of others; unselfish.
Magnanimous means generous or forgiving, especially towards a rival or less powerful person.
Bloated means swollen with fluid or gas.
Capacious means having a lot of space inside; roomy.
Chaste means without unnecessary ornamentation; simple or restrained.