答案已经很明显了吧。

Dá'àn yǐjīng hěn míngxiǎn le ba.

The answer is already obvious.

正确答案是A。

Zhèngquè dá'àn shì A.

The correct answer is A.

我想知道答案是什么。

Wǒ xiǎng zhīdào dá'àn shì shénme.

I want to know what the answer is.