Explanation:

First try to figure out the relationship between the two words in the question pair. Now the words 'implausible' and 'absurd' have almost the same meaning but the usage or polarity is exactly opposite. While 'implausible' is used in positive sense, 'absurd' is used in negative sense. Both have meaning used in the sense of 'unbelievable'. Similarly the option C shows the same relationship. The words 'surprising' and 'shocking' means the same but usage wise both are used in opposite sense(positive and negative respectively).

Hence, opiton 3 is the correct answer.