A two-level quantum system has energy eigenvalues
\( E_1 \) and \( E_2 \). A perturbing potential
\( H' = \lambda \Delta \sigma_x \) is introduced, where
\( \Delta \) is a constant having dimensions of energy,
\( \lambda \) is a small dimensionless parameter, and
\( \sigma_x = \begin{pmatrix} 0 & 1 \\ 1 & 0 \end{pmatrix} \).
The magnitudes of the first and the second order corrections to
\( E_1 \) due to \( H' \), respectively, are:
Which of the following is an octal number equal to decimal number \((896)_{10}\)?