Answer:
(5)- My day was long and exhausting.
Step-by-step explanation:
A topic sentence is a sentence which helps in providing the summary of the whole paragraph. It gives the basic idea of the whole paragraph in one sentence. All the other lines are the additional information which the topic sentence focuses on. In the given paragraph the basic idea of it is to focus on the day spent by the writer. Hence option 5 is the topic sentence of the paragraph.