Which of the following describes a learner who has declarative but not procedural knowledge? A、A learner who knows it's a must to put an "s" on the end of the verb when making third person singular declarative statements, but leaves off the "s" when making such statements. B、A learner who can state or declare the rule, but can't or doesn't use the rule when using the language to communicate. C、A learner who can't state the rule for the third person but does add "s" in statements unconsciously. D、A learner who is able to use the knowledge of language rules for communication.