|A) Observe||B) Speak|
|C) Cheat||D) Act|
"The words in each pair are antonyms of each other". Here "opposite Relationship" exists. The Word Indolence and the word work are opposite to each other. Similarly the opposite of the word Taciturn is speak.
Indolence - Meaning of this word is 'Laziness'
Taciturn - Meaning of this word is ' Saying very little' , not communicating a lot.