Какой вариант???
How did you ___________ around the park?
А: travelled
Б: travel

How did you travel ?

Как ты путешествовал вокруг парка?

Мы не можем добавлять окончание ed, ведь стоит did.

Сравните два предложения:

I did travel around the park.

I travelled around the park.

And...

You did understand me, didn't you?

You understood me, o'key?