(a) The driver of a vehicle approaching an intersection shall yield the right-of-way to a vehicle which has entered the intersection from a different highway.
(b) When two vehicles enter an intersection from a different highway at approximately the same time the driver of the vehicle on the left shall yield the right-of-way to the vehicle on the right.
(c) The right-of-way rules declared in subsections (a) and (b) are modified at through highways and otherwise as hereinafter stated in this article.