About the equation ax^2 \minus{} 2x\sqrt {2} \plus{} c \equal{} 0, with a and c real constants, we are told that the discriminant is zero. The roots are necessarily:
<spanclass=′latex−bold′>(A)</span>equal and integral<spanclass=′latex−bold′>(B)</span>equal and rational<spanclass=′latex−bold′>(C)</span>equal and real<spanclass=′latex−bold′>(D)</span>equal and irrational<spanclass=′latex−bold′>(E)</span>equal and imaginary