Hi guys, is possible to calculate if can use just one linear Bearings or need to use two?

I have 2 models SBR16UU and SBR16LUU

SBR16UU is 45mm length and SBR16LUU is 90mm

i show 3 drawings, top base are MDF 220x170x18mm size

need to choice between these configurations

Option 1 - Use Two Small Bearings



Option 2 - Use just one Small Bearing (45mm)



Option 3 - Use one long Bearing (90mm)


Thanks