Final answer:
The sentence with an inappropriate shift in verb tense is "Dolphins swim together in pods because they were social animals." The shift from present to past tense in the same sentence is incorrect without a specific reason for the change.
Step-by-step explanation:
The sentence that has an inappropriate shift in verb tense is: "Dolphins swim together in pods because they were social animals." The correct verb tense should match the first part of the sentence, which is in the present tense. Therefore, it should be "Dolphins swim together in pods because they are social animals."
When analyzing sentences for correct verb tense consistency, the verb tenses should remain the same throughout a single sentence unless there is a specific reason for a shift, such as a change in the timeframe of the actions described. In this instance, the shift from present tense "swim" to past tense "was" is inappropriate because it suggests dolphins are no longer social animals, which is inconsistent with the fact presented.