Mr. Torrey draws and labels a figure, as shown below. He asks a group of students to each write an expression that is equivalent to the perimeter of the figure in terms of the given side lengths. Clockwise from the top, the figure reads, 5 r, 2 s, 3 r, 2 s, 5 r, 2 s, 3 r, 2 s.

The students’ expressions are shown below.

Brian: $8\left(2r\ +\ s\right)$
Marissa: $2\left(4r\right)\ +\ 2\left(4s\right)$
Clara: $2\left(5r\ +\ 3r\right)\ +\ 4\left(2s\right)$
Alex: $24\ \times\ r\ \times\ s$

Part A
Which expressions are equivalent to the perimeter of the figure? List all of the correct expressions. Show how you know the correct expressions are equivalent to each other.