The excerpt below comes from a speech given by William Jennings Bryan in 1896:

"Having behind us the producing masses of this nation and the world, supported by the commercial interests, the laboring interests and the toilers everywhere, we will answer their demand for a gold standard by saying to them: You shall not press down upon the brow of labor this crown of thorns, you shall not crucify mankind upon a cross of gold."

Which statement explains Bryan's reason for giving this speech?

to convince non-union workers to join the Socialist Party
to convince Congress to pass a minimum wage law
to convince American businessmen to consider human rights as well as profits
to convince Americans to support the expansion of the money supply

In a speech later called the "Cross of Gold" speech, William Jennings Bryan tried to gain the support of Americans to expand the money supply by using the Silver Standard.

Up until 1873, both Silver and Gold backed the American dollar and such could be exchanged for it. This Silver backing was beneficial to the poorer members of the society however it's bountifulness flooded the government's coffers which forced it to take corrective action. Congress removed the silver from backing the Dollar and left only the gold to back it. The poor felt robbed and William Jennings used this to rouse the Democratic support base and win the Democratic nomination for Presidency by using the speech to voice his support for a return back to using silver as well which would increase the currency circulation in the country.