The correct option is
B interested
Option A: The word, "intrigued" means "fascinated". It is used always with the preposition "by". Hence, the sentence, "Tina is intrigued in astronomy" is grammatically incorrect. The correct sentence would be "Tina is intrigued by astronomy". Hence, this option is incorrect.
Option B: The word, "interested" means "showing a curiosity/having a feeling of interest". It is always used with the preposition "in". The sentence "Tina is interested in astronomy" is grammatically correct. It is likely that a person who is interested in astronomy would always be reading about planets and stars". Hence, option B is correct.
Option C: The word, "indolent" means "lazy". A person who is indolent/lazy is not likely to always keep reading. Hence, this option is incorrect.
Option D: The word, "innocent" means "not guilty of a crime". it also means "not having the knowledge of evil / unpleasant things". This word is inappropriate for the given sentence as none of the above meanings are related to what is conveyed in the given two sentences. Hence, option D is incorrect.