To maintain freedom of the seas
"d. People should put their trust in God and their king" was not part of John Locke's work and beliefs, since he believed in rationality and a social contract between the people and their government.
One reason that more people didn’t foresee the economic collapse of the 1930s is that it came about so suddenly, with practically no warning, since the US economy throughout the 20s was thriving and "booming"--leading people to think that there were no issues whatsoever.