Chromium has the electronic configuration \[4{{s}^{1}}3{{d}^{5}}\] rather than \[4{{s}^{2}}3{{d}^{4}}\] because

• A.                 \[4s\] and \[3d\] have the same energy
• B.                 \[4s\] has a higher energy than \[3d\]
• C.                 \[4{{s}^{1}}\] is more stable than \[4{{s}^{2}}\]
• D.                 \[4{{s}^{1}}3{{d}^{5}}\] half-filled is more stable than \[4{{s}^{2}}3{{d}^{4}}\]