Read the following context and choose the best option to answer the question.
Context: So , time for a post , been a while , posting on MS and other places . I was let go from my job last monday , mostly because I was getting cocky and people were tired of it , but I have been there for 10 years and they kinda need me to keep things running so after a week , my boss managed to get the others to keep me on for at least 6 months and then re - evaluate . Meanwhile , I started applying for new jobs right away and found a few that pay a lot more , so things can go either way at this point .
Question: What may be the reason for them getting fired ?
Options: 
- They had been making their boss upset .
 - They had been causing problems at their job .
 - They had been showing up late to work .
 - They had been doing poorly at their job .


They had been causing problems at their job .