Ruby Quiz questions

Question_4.rb

# Reddit thread: http://www.reddit.com/r/ruby/comments/217yvm/trivia_ruby_quiz/
# Quiz page: http://makaroni4.com/ruby/quiz/2014/03/24/ruby-quiz/
# Explanation link: http://www.medihack.org/2011/03/15/intend-to-extend/

# Code example:

module Human
  def eat
    puts "Yam"
  end
end
 
class Robocop
  def shoot
  end
end

class User
  extend Human
end

User.eat # => Yam

class User
  extend Human
  extend Robocop
end

# => wrong argument type Class (expected Module)