In the given IR spectrum, the C-H stretching vibration has a range of 2850-3000-1 cm with high intensity. The CH2 and CH3, bending vibrations are also seen around 1450 cm-1 and 1350 cm-1 respectively. The C=C stretching vibrations are seen at 1600 cm-1 ?. There is no carbonyl, hydroxyl, amine or C-O stretching vibrations are present. Thus the correct answer is pentane; option is 'C'.