Which of the quantities listed below concerning an electron...

According to the special theory of relativity, no material particle can travel at or faster than the speed of light in a vacuum, $c$.

Therefore, the speed of an electron has a finite upper limit, $v < c$.

The relativistic mass of an electron is given by $m = \dfrac{m_0}{\sqrt{1 - \dfrac{v^2}{c^2}}}$. As $v \rightarrow c$, $m \rightarrow \infty$. Thus, mass does not have a finite upper limit.

The momentum is $p = mv$. As $m \rightarrow \infty$ and $v \rightarrow c$, $p \rightarrow \infty$. Thus, momentum does not have a finite upper limit.

The kinetic energy is $K = (m - m_0)c^2$. As $m \rightarrow \infty$, $K \rightarrow \infty$. Thus, kinetic energy does not have a finite upper limit.