Passage: Read the given passage and answer the questions that follow. My son was two when we had been discharged from hospital following a nasty winter bug. His birthday was a few days away with no time to plan for a big party, so I invited a close family friend and her kids to a teddy bear-making workshop followed by a pizza. She agreed, huge relief – the problem was solved. But then she cancelled last-minute because apparently her children had received a better offer from a popular classmate who hosted great parties! My friend realised quickly that her honesty had fallen flat with me and so she came over to apologise. Research shows that apologies are most convincing when they involve greater cost, such as in terms of money or time. My friend seemed to know this intuitively – she turned up on my doorstep (time cost) with a bottle of champagne (financial cost) at a time that would have likely inconvenienced her (effort cost). Newer research shows that people judge apologies involving longer words of explanation (I did not mean to respond in a confrontational manner) as more convincing than apologies involving shorter words (I did not mean to answer in a hostile way), presumably because they signal greater cognitive c o s t . Question: In the passage, the word ' convincing' is used. Which of the following is the ANTONYM of that word in this context?

1. compelling
2. indifferent
3. valid
4. implausible