The correct option is C Little
The option with the opposite meaning is the correct one.
The
underlined word 'astronomical' means 'extremely large' (amount of money).
Option
A: 'Little' means 'small in size or amount'; it's the complete opposite of the underlined word. Hence A is the correct option.
Option B: 'Commercial' refers to trade and business, it relates to the sentence in terms of context, as the sentence talks about house rent which is a profit-oriented business.
Option C: Similarly, 'planetary' relates to planets. 'Astronomical' also means 'relating to astronomy or celestial objects, like planets. (But, the context of the sentence does not suggest the same.) Hence, 'planetary' is not an antonym of the given word.
Option D: 'Illogical' means 'lacking sense or logic'. The sentence somehow implies that these astronomical figures lack sense, hence the word isn't an antonym.
Since each of these words are related to the sentence, they are not antonyms here. (An antonym is a word that is opposite in meaning to another.)
Hence options B, C and D are incorrect.