The answer is D. Restatement
The first sentence states, "America has defaulted" or has not carried through with a promise, or "promissory note" to people of color. The idea expressed is that America does not make do on its promises. This idea is restated in the second sentence. The promissory note is symbolically shown as a bad check, or an unresolved action that is not provided to "the Negro people". The restatement is extended further as a "check that has come back marked "insufficient funds". Disregarding a promise (promissory note) is restated as a bad check labeled insufficient funds.