I would say four ! because makes sens
Ancient Rome had a republic, just like the United States. Romans also had unofficial branches of the government, like judicial, executive and legislature. Both of the governments had a legal code. In Rome's case, it was the Twelve Tables. In the US, it is the Constitution.
Hope this helps.
The answer is D. Adding “ ,and” turns the sentence into a compound sentence
I'd say C, "The acrylic pods are created in many sizes, including big, small, and medium, as well as other sizes needed by the scientists; they are connected to the seafloor by chains and float some distance below the surface, so the plants are not destroyed by storms."