Mips coding questions

Which of the following is TRUE? (Select all that apply) It is the callee function's responsibility to maintain the correct position of the stack pointer. The stack grows downward in memory. A function uses the stack to preserve register values while it performs its operation. It is the responsibility of the callee function to always preserve all of the saved registers ($50-$57) on the stack. The stack pointer ($sp) should alway points to the current top of the stack. The caller function places the values in the saved registers ($50-$57) on the stack prior to every function call and replaces them into the saved registers after returning from the function call