Answer: the modification adds distinct goods or services at a price that reflects their stand-alone selling price.
Step-by-step explanation:
When multiple goods or services are offered in the same contract they are not usually given their standalone price but rather a contract price that is less as a form of discount for getting all the goods at the same time.
When a modification is added however, that reflects the standalone price of goods added, the contract has to account for the contract modification because there are now multiple pricing conventions and this needs to be accounted for.