Small script to help rank the values in an array from user input

choose.rb

class Array
  CHOOSE_OPTIONS = {'a' => -1, 'b' => 1, 'c' => 0}
  def choose
    self.sort! do |x, y|
      answered = false
      begin
        puts "Which do you prefer?"
        puts "  (A) #{x}"
        puts "  (B) #{y}"
        puts "  (C) Neither"
        response = gets.strip.downcase
        if CHOOSE_OPTIONS.has_key?(response)
          answered = true
        else
          puts "#{response} isn't an option"
        end
      end until answered
      Integer(CHOOSE_OPTIONS[response])
    end
  end
end