Final answer:
Terms referring to true statements are Theorem, Fact, Result, and Corollary. Lemma and Conjecture do not inherently refer to truth, as they represent propositions that are not proven to be true until proven. The term closest to hypothesis in meaning is suggestion.
Step-by-step explanation:
The terms which refer to true statements in the context provided are Theorem, Fact, Result, and Corollary. A theorem is a statement that has been proven on the basis of previously established statements, such as other theorems, and generally accepted statements, such as axioms. A fact is information that is true and can be proven correct or accurate, often based on evidence and data. A result is a conclusion drawn from a mathematical proof, experiment, or survey. A corollary is a statement that follows readily from a previously proven statement. In contrast, a lemma is a helping theorem or a proposition that is not necessarily true by itself until it's proven and used to assist in proving another theorem. A conjecture is a tentative statement that has not yet been proven or shown to be true.
When looking for a word that is closest to the same meaning as hypothesis, the most appropriate choice would be d. suggestion. A hypothesis is a proposed explanation for a phenomenon. It is a starting point for further investigation and is not yet confirmed or accepted as a fact.