Some people think that high levels of testosterone hormones are the main cause of heart attacks in men. However, this view is wrong because men with heart disease generally have lower testosterone levels than men without heart disease. The above discussion is based on which of the following assumptions? ['Many men who have never had heart disease usually have low levels of testosterone.', 'Heart disease does not significantly reduce testosterone levels in men.', "Hormonal levels other than testosterone significantly affect a person's likelihood of developing heart disease.", "Men's heart disease and lower testosterone are a consequence of the same cause."]