It seems like a missed opportunity to use the "salutationes faciunt" construction we've learned.
I thought that, but wrong time of day? I think it's a trick question.
If you hold the mouse over the hints section it actually gives Salutationes faciunt as first suggestion so it should accept that.
This is what I typed 2020-12-02, and it was accepted, but it told me I should have used salutationem. But what if it's several people making separate visits?
It's a pity it didn't outright mark you wrong. Otherwise you would have had the option to report "My answer should be accepted."
Salutationem faciunt was accepted for me. 21 March 2020
Is "quartam horam" accusative here? Is there a reason for that?
Because it's the object of the preposition "ante".
why quartam horam and hot horam quartam
Adjectives of number typically come before the noun. This survives in the modern Romance languages.