Final answer:
The sentence is in the correct past continuous tense, matching the singular first-person subject 'I'. The phrase 'was having' should remain unchanged, so the answer is option 4) no change.
Step-by-step explanation:
The word was having should not be changed in the sentence 'I was having a delicious meal at Tuff pizza when I saw a cat get stuck in the tree.' The sentence is already in the correct past continuous tense, which is used to indicate that a past action was in progress at a specific time in the past.
The words 'was having' correctly align with the singular first person subject 'I'. Therefore, the correct answer is no change.