Concept:An antonym is a word that means the opposite of another word.
Explanation:The word 'Abound' means 'to exist in large numbers' or 'to be plentiful'.
The opposite of 'Abound' should express scarcity or absence.
The word 'Lack' means 'the state of being without' or 'not having enough of something'.
Thus, 'Lack' is the exact opposite in meaning to 'Abound'.
The other options do not give the opposite meaning.
'Bless' means to ask God to look favourably on someone.
'Discourage' means to cause someone to lose confidence or enthusiasm.
'Rest' means to cease work or movement in order to relax.
Hence, none of these are antonyms of 'Abound'.
Answer:Option D: Lack.