單項選擇題某規(guī)劃包含三個規(guī)劃項目,經(jīng)計算A規(guī)劃項目D10%為20km,B規(guī)劃項目D10%為30km,C規(guī)劃項目D10%為45km,則該規(guī)劃大氣環(huán)境影響評價范圍以規(guī)劃區(qū)邊界為起點,外延()的區(qū)域。

A.20km
B.30km
C.45km
D.50km