When a Noun Clause Is the Object of a Verb

When a noun clause is the object of a verb, are there verbs that always or never assert the proposition in the noun clause?

A) No, because whether or not a proposition is asserted never depends on the verb.
B) No, each verb asserts the proposition sometimes, but not other times.
C) There are verbs that never assert the proposition, but none that always do.
D) There are verbs that always assert the proposition, but none that never do.
E) Yes, some verbs always assert the proposition, while others never do.