So can you give us the choices ? lol
I believe the right answer would be C) monitor.
Monitor can be a noun; "I have many monitors."
Or a verb; "I'll be able to monitor that soon."
You can try and use a website called "essaytyper"
https://www.google.co.il/url?sa=t&source=web&rct=j&url=http://www.essaytyper.com/&ved=0ahUKEwjo2ejWkMjMAhWEthoKHbZVCXUQFggZMAA&usg=AFQjCNFwouC2BTYfkMolos7xZtypikaUfg&sig2=agdG-xRxRrum1I49HNKV6w