The answer is D. On April 19, 1783, the US Congress ratified a preliminary peace treaty and five months later, the US and Britain signed the Treaty of Paris and British troops left New York City in November.
Step-by-step explanation:
A sentence is classified as run-on if two or more ideas are included without proper punctuation or transitions to separate them which makes the sentences lack necessary pauses. This grammatical error occurs in the last option because a comma needed to be included between the sentence "The US and Britain signed the Treaty of Paris" and the sentence "and British troops left New York City in November" considering these two sentences are complete and independent. Therefore, this sentence is missing proper punctuation and thus, it is a run-on sentence.