The correct answer is C) The difference in height between consecutive high or low tides is at a minimum. Equatorial tides occur when the Sun and Moon are over the equator, causing the tidal bulges to be equal on both sides of the Earth. This results in the difference between consecutive high or low tides being at a minimum, as the tidal range is reduced. The other options are incorrect - option A refers to spring tides, option B refers to perigean tides, and option D refers to the vulgar establishment, which is not directly related to equatorial tides.