### A good answer might be:

See Below.

# Complete `mysub()`

    #  int mysub( int arg )
    #  {
    #    int b,c;                     // b: 0($fp)
    #                                 // c: 4($fp)
    #    b = arg*2;
    #    c = b + 7;
    #
    #    return c;
    #  }
             .text
             .globl  mysub
    mysub:
                                      # prolog
             sub     $sp,$sp,4        #   1. Push return address
             sw      $ra,($sp)
             sub     $sp,$sp,4        #   2. Push caller's frame pointer
             sw      $fp,($sp)
             sub     $sp,$sp,4        #   3. Push register $s1
             sw      $s1,($sp)
             sub     $fp,$sp,8        #   4. $fp = $sp - space_for_variables
             move    $sp,$fp          #   5. $sp = $fp

                                      # body of subroutine
             mul     $s1,$a0,2        #     arg*2
             sw      $s1,0($fp)       # b = "   "

             lw      $t0,0($fp)       # get b
             add     $t0,$t0,7        #     b+7
             sw      $t0,4($fp)       # c = "  "

                                      # epilog
             lw      $v0,4($fp)       #   1. Put return value in $v0
             add     $sp,$fp,8        #   2. $sp = $fp + space_for_variables
             lw      $s1,($sp)        #   3. Pop register $s1
             add     $sp,$sp,4        #
             lw      $fp,($sp)        #   4. Pop $fp
             add     $sp,$sp,4        #
             lw      $ra,($sp)        #   5. Pop $ra
             add     $sp,$sp,4        #
             jr      $ra              #   6. return to caller

### QUESTION 14:

What must the caller do when control returns to it?