Differntiation of Time Risk Signs - Rx & Lx

 Observe the dirrentiation of  Time Risk signs, which one is considered the most important sign ?

   1) Orange Pigment co-sign with lacuna at 135'

  2)  Local indented lacuna co-sign with orange pigment 102' 

 3) Collarette Bridge - TR 2

 4) Local indentation of the lacuna - TR3