What does the term cardinal imply?

The term "cardinal" refers to something that is essential or fundamental, signifying its importance or primary nature. In many contexts, such as mathematics and philosophy, "cardinal" denotes the foundational elements or principles that are crucial to the understanding of a concept or system. For instance, in mathematics, cardinal numbers represent the size of a set, emphasizing their fundamental role in counting and quantifying.

The other options suggest meanings that do not align with the definition of "cardinal." For example, unimportant or secondary implies a lack of significance, which is contrary to the primary nature implied by the term. Optional or discretionary conveys a sense of choice rather than necessity, while unrelated and irrelevant suggests a complete detachment from relevance or importance, which again misses the critical essence that "cardinal" embodies. Thus, "essential or fundamental" aptly captures the core meaning of the term.