When combing our hair in dry weather, occasionally the hair can fly apart. This is the result of the _______ force.

• When two objects are rubbed together, there is an exchange of electrons.
• While combing hair in dry weather, some electrons from hair follicles are transferred to the comb. 
• As a result, the hair follicles develop positive charges on them.
• Since like charges repel each other, the hair follicles exert electrostatic force and start repelling each other.

Therefore, 'Electrostatic force' is the correct response.