Which of the following is an inaccurate statement about public goods?
a. public goods are nonrival: one person's consumption doesn't diminish another's.
b. public goods are shared goods or services that wouldn't necessarily be available if they were provided privately.
c. public goods are nonexcludable: people can't be excluded from using them.
d. public goods are provided by private firms.

frederick william of brandenburg-prussia trained his son, frederick, to be a hardy soldier. but frederick disliked rifle shooting and horseback riding. unlike his father, he was interested in french literature. he enjoyed poetry and music and, like some others of the enlightenment, he scoffed at religion. his father thought him soft, frivolous and unmindful of his duties. and when frederick refused to put his signature on a right to succession, for a few moments his father strangled him.