Which of the following is an example of a positive externality problem? Group of answer choices Overgrazing of open range lands resulting in degradation of those lands. Severely polluted air resulting from weak air emissions regulations. Sub-optimally lows levels of investment in rooftop solar energy because many of the environmental benefits of rooftop solar do not accrue directly to solar users. Sub-optimally high levels of investment in wind energy development resulting solely from the subjective, altruistic preferences of a handful of billionaires. None of the above are example of a positive externality