Final answer:
A synonym for "trend" as a noun is "tendency." In scientific and mathematical contexts, a "variable" is something whose value can change, and a "hypothesis" is closest in meaning to a "suggestion."
Step-by-step explanation:
A synonym for "trend" as a noun is "tendency." The word "trend" refers to a general direction in which something is developing or changing. A "tendency" also indicates a direction or inclination, making it the best synonym among the options provided. Hence, the correct answer is a) Tendency.
Addressing other parts of the provided reference information, a "variable" in the context of scientific measurements or mathematics is something whose value can change over multiple measurements, which fits the given option b. In relation to hypotheses, the word that is closest in meaning to "hypothesis" is "suggestion", because a hypothesis is a proposed explanation that is based on limited evidence and requires further investigation. Therefore, the closest answer to that is d) Suggestion.