None of them implies specifically "he", but it has to be either "he, she, it" because the verb form έχει is for third person singular.
It's probably either "he" or "she", because things that we refer to as "it" in English (inanimate objects, mostly) generally don't own things.
(But all three are accepted. Some people might refer to a young child as "it", for example, and it might own a cat.)
"does he have" -- the -s for "he" goes onto the "do" helping verb in this question.
Generally, when there are two verbs in a sentence, only one of them gets the -s ending for "he, she, it", or a past tense ending, or other change, and the other one is in the dictionary form.
DOES he HAVE " When there is the helping verb DOES then you use HAVE because the "S" is on DOES.
You can find this in the Tips & notes for Basic 1.
See here for how to find that and more helpful links.
TIPS TO HELP YOU LEARN + HOW TO REPORT A PROBLEM
And check out the Greek Forum here with more links. https://forum.duolingo.com/topic/936