Final answer:
The High Liquid Level Switch is usually Normally Closed and Opens on an increase in liquid level; hence, it 'Opens on increase (rise)' would be its typical behavior.
Step-by-step explanation:
The behavior of a High Liquid Level Switch typically depends on its design and application. However, most commonly it operates as follows: it is Normally Closed (NC) and Opens on increase (rise) in liquid level, thereby providing a signal to another system component that the high liquid level has been reached. So, for the options provided, 2) Opens on increase (rise) would be the correct behavior. The switch would return to its closed state on a decrease (drop) in the liquid level, which isn't one of the given options, but it's useful to understand the complete cycle of operation.