Are the following statements true or false?

a) “If the assumptions of the median voter model hold, then using majority voting to determine the amount of a public good purchased by a city will lead to either an efficient level of the public good being provided or an under-provision of the public good. It cannot lead to an over-provision of the public good.”

b) A prominent senator has calculated the total social benefit of the current amount of space exploration at $3 billion per year. The total social cost of space exploration is currently only $2 billion. The senator argues that there would be a net gain to society by increasing the amount of space exploration until total costs rise enough to equal total benefits. Is the senator correct?