To be included as a genuine cost component, the training in question should relate to safety, as per SCC People category 13 (o). Note that the cost must also be incurred in order to Provide the Works, so any general training requirements, such as corporate procedures, would deemed to be included in the Fee.
The simplest way to calculate a cost is to assess the 'lifecycle' cost from the date when the training is given to the date when the qualification expires, Calculate the period of time when the person is working on Providing the Works and pro-rata this. Note that some training may be very 'project specific' so in these circumstances you would probably negotiate a sensible apportionment of cost.
Option C is intended to cover the 'cost to employ', which would include periodic training and renewal of licences, etc, so should be included as part of the assessment, where such costs appropriately fall under a category in the Schedule of Cost Componenets.