Final answer:
The term synonymous with 'union' is 'unity'. Among the additional questions given, the idea that people's views should match their actions is 'congruence', the closest term to hypothesis is 'suggestion', and the Gestalt law favoring smooth paths in visuals is 'good continuation'.
Step-by-step explanation:
The term that is synonymous with "union" in the context of combining or joining is b) Unity. The word unison often refers to things happening at the same time or a simultaneous action, but it may not necessarily imply a combination or a join. The term element does not suggest a joining but rather a singular part of a whole, and congruity suggests harmony or agreement rather than a union. Therefore, among the given options, 'unity' best captures the synonymous meaning of a union.
In response to the other parts of the question:
- The idea that people's ideas about themselves should match their actions is called d) congruence.
- The word closest to the same meaning as hypothesis is d) suggestion because a hypothesis is a proposed explanation that needs to be tested, similar to a suggestion.
- According to Gestalt psychology, the tendency for our perception to favor smooth or continuous paths in visual elements over choppy or jagged lines is referred to as b) good continuation.