For transferring the tunnel alignment through shafts, we adopt the following steps : 1. Hanging two or more plumb lines in the shaft 2. Determining the bearing of the plumb lines i.e. plumb plane 3. Suspending a 35 kg weight by each plumb line 4. Immersing the weights of both the plumb lines in the buckets containing water. The correct sequence of steps is :

• 1 2 3 4
• 4 3 2 1
• l 3 2 4
• 2 1 4 3