Ruby Program not working

class String
def black;          "\033[30m#{self}\033[0m" end
def red;            "\033[31m#{self}\033[0m" end
def green;          "\033[32m#{self}\033[0m" end
def brown;          "\033[33m#{self}\033[0m" end
def blue;           "\033[34m#{self}\033[0m" end
def magenta;        "\033[35m#{self}\033[0m" end
def cyan;           "\033[36m#{self}\033[0m" end
def gray;           "\033[37m#{self}\033[0m" end
def bg_black;       "\033[40m#{self}\033[0m" end
def bg_red;         "\033[41m#{self}\033[0m" end
def bg_green;       "\033[42m#{self}\033[0m" end
def bg_brown;       "\033[43m#{self}\033[0m" end
def bg_blue;        "\033[44m#{self}\033[0m" end
def bg_magenta;     "\033[45m#{self}\033[0m" end
def bg_cyan;        "\033[46m#{self}\033[0m" end
def bg_gray;        "\033[47m#{self}\033[0m" end
def bold;           "\033[1m#{self}\033[22m" end
def reverse_color;  "\033[7m#{self}\033[27m" end
end
puts "We now need to ask you some questions to prove that you are a human.".green.bold.bg_cyan
stop = false
tries = 0
while stop == false
    win = 5
    puts "Which of the following is NOT a real country?".green.bold
    puts "  a\) Sudan".blue
    puts "  b\) Canada".blue
    puts "  c\) The Yukon".blue
    puts "  d\) Luxembourg".blue
    questionOne = gets.to_s
    if questionOne != "c"
        win -= 1
    end
    puts "Which of the following is traditionally made in Russia?".green.bold
    puts "  a\) Vodka".blue
    puts "  b\) Ale".blue
    puts "  c\) Wine".blue
    puts "  d\) Whiskey".blue
    questionTwo = gets.to_s
    if questionTwo != "a"
        win -= 1
    end
    puts "What is the square root of 49?".green.bold
    puts "  a\) 3.14".blue
    puts "  b\) 16".blue
    puts "  c\) Impossible!".blue
    puts "  d\) 7".blue
    questionThree = gets.to_s
    if questionThree != "d"
        win -= 1
    end
    puts "What is the scientific name of humans?".green.bold
    puts "  a\) Humanus Intelligentio".blue
    puts "  b\) Primanus Homo".blue
    puts "  c\) Homo Sapiens".blue
    puts "  d\) Primanus Brilliante".blue
    questionFour = gets.to_s
    if questionFour != "c"
        win -= 1
    end
    puts "What is the terminated Skylanders mmo called?".green.bold
    puts "  a\) Skylanders: Spyro's Adventure".blue
    puts "  b\) Skylanders: Universe".blue
    puts "  c\) Skylanders: Battlegrounds".blue
    puts "  d\) Skylanders: Lightning Rod versus The Cyclops Queen".blue
    questionFive = gets.to_s
    if questionFive != "b"
        win -= 1
    end
    if win >= 5
        win = 5
    end
    if win > 3
        haveWon = true
        puts "You've Won! Welcome to Sky Tech".green
        stop = true
    else
        tries += 1
        if tries == 10
            stop = true
            puts "You have failed!".red
            haveWon = false
        end
    end
end