Allhomes Contracts with Baker Contractors for the Construction of 75

Allhomes contracts with Baker Contractors for the construction of 75 housing units for £17 million. The contract specifies that Baker must use foam insulation for the hot water pipes. Instead, Baker uses foil-faced fiberglass insulation as he usually does. Replacing the insulation would entail demolishing all inner walls of the constructed house, costing £11 million. The two types of insulation are equal in value and are identical for all practical purposes. What damages can Betterhomes claim for the breach?

A) The cost of cure, being the cost of replacing the insulation (£11 million) .
B) The diminution of value (nominal) .
C) The loss of amenities (a just sum determined by the courts) .