Consider the following statements about a polynomial $f(x)$:

I $f(x)=p{x}^3+q{x}^2+rx+s$, where $p\ne 0$.

II There is a real number $t$ for which $f^{\prime }(t)=0$.

III There are real numbers $u$ and $v$ for which $f(u)f(v)<0$.

Which of these statements is/are sufficient for the equation $f(x)=0$ to have a real solution?

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