Tamen dou1 hen3 hao3
Most likely it's the first meaning.  I would give the second as 都可以 'dou1 ke3yi3' in the sense of 'both are possible'.  Dou1 actually means 'all', but obviously it can refer to two items as well.  Anyway isn't the sentence in context in the book?

It's nice to indicate the tones too when you write pinyin, it might help others identify the words.