\[y = x^{2} - 4x + 6;\ \ y = 11\]
\[x^{2} - 4x + 6 = 11\]
\[x^{2} - 4x - 5 = 0\]
\[D = 16 + 20 = 36 > 0 - два\ решения.\]
\[Ответ:В.\]