Which of the following is a complete sentence?
A. Walking with a limp as a result of the thorn.
B. I walked all three dogs around the park this morning.
C. Running through the park before breakfast.
D. When I was young and loved going for runs in the park.
A complete sentence must have a subject and a predicate that expresses a complete thought. Option B, "I walked all three dogs around the park this morning," is a complete sentence because it has a subject ("I") and a predicate ("walked all three dogs around the park this morning") that expresses a complete thought.
Therefore, the Correct Answer is B.