Obviously the correct answer is both, but if you had to choose.  It's a tough choice, but I'd go with Shauna.  Only because she gave me Chespin after i beat the game. 

*this thread is a joke btw :P. 

Added poll.

Aren't they both like... underaged? But if they aren't I guess it would be Shauna cause her hair has some pretty damn interesting physics going on there

They both look terribly under aged.

Anything you'd like to share with us?

This would not be questioned if we lived in Japan.  Why's it questioned here?  Besides.  They could be 18.

Serena gives off the friend zone feeling or Shauna acts like she might have feelings for you.

But only if I was like a decade younger. ;p

Considering the proposed loli ban in Japan and the whole turmoil that's come up in recent years, I think it's questioned plenty there as well.

How can I answer if I don't know who is who in the picture?

PDF files everywhere.

http://ja.wikipedia.org/wiki/%E3%82%BB%E3%83%AC%E3%83%8A_(%E3%82%A2%E3%83%8B%E3%83%A1%E3%83%9D%E3%82%B1%E3%83%83%E3%83%88%E3%83%A2%E3%83%B3%E3%82%B9%E3%82%BF%E3%83%BC)

セレナ
ポケットモンスターのキャラクター
登場（最初） XY1話「カロス地方にやってきた! 夢と冒険のはじまり!!」
声優 牧口真幸
プロフィール
年齢 10歳
性別 女性
親戚 母

Ten years old dude.