The correct answer is C. Marina and Kayla’s toys are under the bed.
Step-by-step explanation:
In grammar, the apostrophe (’) is a punctuation mark mainly used with two purposes the first one is to show the omission of letters in contractions, for example in "I’m" which derives from the words "I am" the apostrophe is used to show the letter "a" and space between both words have been omitted. On the other hand, the apostrophe (’) is used to express possession or belonging in this case it is common to add an apostrophe (’) and "s" to show possession or just an apostrophe if the word already ends in "s", for example in the phrase "Carla’s notebook" the apostrophe shows the notebook belongs to Carla.
Additionally, in case there are two or more subjects that own an object the apostrophe should be placed at the end of each subject if the ownership is individual or just at the end of the last subject or person is the ownership is joint. Considering this, it can be concluded the sentence that correctly uses apostrophe to show joint ownership is "Marina and Kayla’s toys are under the bed" because in this sentence the use of apostrophe at the end of both names and not an apostrophe in each name shows the toys are owned by both "Marina and Kayla", also the use of the apostrophe is correct as the apostrophe is used and then an "s" is added.