Is present continuous implicit here?
Answer and reply to are standard synonyms
No, present simple should also be accepted (and it was, just now).
"Answer" and "reply to" are near synonyms but not quite a full match.
I used "reply" - what is the difference between answer and reply?
"answer" can be transitive (take a direct object - in this case "the question").
"reply" is intransitive ("reply to" + object, or just the verb alone: " 'Yes', she replied.")