Caligula is singular, not plural. I wrote small boot, but it was not accepted. For the death of Julius Caesar I wrote March 15, or 44BC, no acceptance.
The write ins for this quiz are really bad. Currently only 40% of people got "who is the founder of Rome" correct because the only acceptable answer is "Romulus Remus", even though I'm sure 90% of the people taking the test know. Also, what type of answer is "abduction?" It's correct but why is getting the answer right based on your choice of specific vocabulary?
Ides of March? Most people would assume the year is intended! Centuries had varying numbers of soldiers from 60 to 100 depending on the state of security.