Pick up the correct statement from the following:

• The earth work of cutting in trenches or borrow pits in fairly uniform ground is measured with the help of average depths of the dead men
• The earth work in trenches or borrow pits in irregular ground is measured by taking the difference in levels before and after completion of work
• The earth work in trenches or borrow pits, where neither a nor b is feasible, are measured from the fillings after deduction of voids
• All the above.