In the theoretical landscape of second language acquisition, Stephen Krashen's Monitor Model and Noam Chomsky's nativist theory propose distinct cognitive mechanisms for human linguistic capacity. Consider the following four advanced theoretical propositions: I. Krashen's Affective Filter Hypothesis posits that emotional variables such as anxiety, self-confidence, and motivation can act as an adjustable mental block that prevents incoming comprehensible input from reaching the language acquisition device, thereby determining whether acquisition occurs. II. Chomsky's nativist paradigm argues that primary linguistic input received by children is degenerate, impoverished, and incomplete (the 'poverty of the stimulus' argument), yet children effortlessly construct complex grammars, proving that core syntactic principles are biologically pre-programmed. III. Krashen's Acquisition-Learning Hypothesis maintains that 'acquisition' is a conscious, deliberate process resulting from formal classroom instruction and explicit rule memorization, whereas 'learning' is a subconscious process akin to child first-language development. IV. Within Krashen's Monitor Hypothesis, the learned system functions exclusively as an editor or monitor that may alter the output of the acquired system only when the speaker has sufficient time, focuses on grammatical form, and possesses explicit knowledge of the rules. Identify the option that correctly evaluates the theoretical and pedagogical validity of propositions I, II, III, and IV according to standard second language acquisition theory and Second-language acquisition principles.