Final answer:
The correct plural form is 'The California Raisins'. This follows the standard rule of adding an 's' to a noun to make it plural. The other options are either showing possession or are misspelt.
Step-by-step explanation:
The correct plural form of the claymation musical group is The California Raisins. When forming the plural of nouns in English, we typically add an 's' or 'es' to the end of the word. In this case, 'Raisin' is a noun that simply takes an 's' to become plural, changing it to 'Raisins'. Therefore, option a) The California Raisins is correct. Options b) and c) are incorrect because 'Raisin's' implies possession, which is not relevant here, and 'Raisens' is a misspelling. Option d) is incorrect as it represents a singular term and does not indicate a group.