【单选题】
一个n位字长的采样,其样本值映射到( )之内。
①
<img class="kfformula" src="20200528/1590626423354468.png" data-latex="0\sim {2}^{n}" width="94" height="39"/>
②
<img class="kfformula" src="20200528/1590626423162963.png" data-latex="0\sim {2}^{n}+1" width="131" height="43"/>
③
<img class="kfformula" src="20200528/1590626423471895.png" data-latex="{2}^{n}" width="62" height="40"/>
④
<img class="kfformula" src="20200528/1590626423983895.png" data-latex="0\sim {2}^{n}-1" width="133" height="42"/>