[单选题]
An object is 6.0 cm .,c2cr k5(q jb4 v4rygnw8ilitall, and i4:hcpsb yiwf.,4hm ogryd 04,mf05wjs in front of a diverging lens. The image is 2.5 cm tall, and 7.5 cm from the lens. Whs 40bg c do f.4hwfy 4pmj,iwy,m0:hr5at is the focal length of the lens?
