Step 1: A secondary hydrogen is one that is attached to a carbon atom that is itself attached to two other carbon atoms.
Step 2: In 2,2,3-Tetramethylpentane, the carbon atoms at positions 2 and 3 have two other carbon atoms attached, and the hydrogens attached to these carbons are secondary hydrogens.
Step 3: Other options do not exhibit the same secondary hydrogen placement.
Thus, the correct answer is 2,2,3-Tetramethylpentane.
Complete the following reactions by writing the structure of the main products: 
0.01 mole of an organic compound (X) containing 10% hydrogen, on complete combustion, produced 0.9 g H₂O. Molar mass of (X) is ___________g mol\(^{-1}\).