Answer: dispersion forces
Step-by-step explanation:
Dispersion forces arise due to temporary shifts in the electron cloud of a molecule. This creates a temporary dipole which could attract another molecule of exactly the same kind, inducing a temporary dipole in the other molecule also and so on. Dispersion forces occur in non polar molecules such as alkanes and are the principal intermolecular forces in operation in such compounds. The given compound is an alkane hence dispersion forces are of paramount importance.