[单选题]
A microscope has an objec:axyjp4f/ s ny)d. xt;tive l v;c3n;lkeu)o6xcw(g aafk.-ens of focal length 1.4 mm and an eyepiece of focal length 20 mm, adjusted for minimum eyestrain. A blood sample is placed 1.5 mm from the objective. What is the overa6 f cl;uk wxka.n)agv;3(co -ell magnification?
