Pick up the correct statement from the following:

• The incidental expenses of a miscellaneous character which could not be predicted during preparation of the estimate, is called contingencies
• Additional supervising staff engaged at work site, is called work charged establishment
• Detailed specifications specify qualities, quantities and the proportions of materials to be used for a particular item
• The cost per unit at which the article can be procured, from the open market at a given time, is called 'market rate'
• All the above.