What is the correct way to write sentences 27 and 28?

That summer was one of the busiest we've ever had, the money my sisters and I made helped
pay the water, electric, and gas bills.
B While that summer was one of the busiest we've ever had. The money my sisters and I made
helped pay the water, electric, and gas bills.
It was one of the busiest we've ever had. Because the money my sisters and I made that
summer helped pay the water, electric, and gas bills.
The sentences are written correctly in the paper.

The correct way to write sentences 27 and 28 can be improved for clarity and flow. Here are the revised versions:

27. That summer was one of the busiest we've ever had, and the money my sisters and I made helped pay for the water, electric, and gas bills.

28. It was one of the busiest summers we've ever had. The money my sisters and I made that summer helped cover the expenses for water, electricity, and gas bills.