單項(xiàng)選擇題

計(jì)算單側(cè)采光的采光系數(shù)時(shí),其計(jì)算點(diǎn)應(yīng)選在圖中哪一點(diǎn)?

A.點(diǎn)1
B.點(diǎn)2
C.點(diǎn)3
D.點(diǎn)4