look 、taste 连系动词,后面接形容词作表语,说明主语所处的状态.
所以选D tasty good

What do you think of the fish?
你觉这条鱼怎样?

It looks tasty,but I don't know if it tastes good.
看起来很可口,但我不知道它吃起来好不好吃.