The table below shows the concentration of carbon dioxide in arbitrary units (a.u.\text{a.u.}a.u.) inside and outside four different active cell lines, WWW, XXX, YYY, and ZZZ.
| Cell line | Carbon dioxide concentration inside (a.u.\text{a.u.}a.u.) | Carbon dioxide concentration outside (a.u.\text{a.u.}a.u.) |
|---|---|---|
| WWW | 24 | 16 |
| XXX | 19 | 21 |
| YYY | 32 | 21 |
| ZZZ | 15 | 16 |
Based on the data provided, answer the following questions:
Which cell line has the smallest difference in carbon dioxide concentration between the inside and the outside of the cell?
Out of which cell line will carbon dioxide diffuse out of the fastest?