The staff reading taken on a workshop floor using a level is $0.645$ m. The inverted staff reading taken to the bottom of a beam is $2.960$ m. The reduced level of the floor is $40.500$ m. The reduced level (expressed in m) of the bottom of the beam is

1. $44.105$
2. $43.460$
3. $42.815$
4. $41.145$