Answer:
ribosome
Explanation:
its a math problem applied in bio subject
convert all dimensions in sci notation:
nucleus: 1/100,000=1x10^-5
mitochondrion: 0.000001=1x10^-6
chloroplast: 3x10^-6
ribosome: 2.3x10^-8
golgi body: 0.000003=3x10^-6
10^-x gets smaller as x gets bigger
so the smallest dimension is ribosome @ 2.3x10^-8