Final answer:
The correct proficiency codes to identify subject knowledge depend on the specific context and the standards of the educational or testing institution. There isn't a universally accepted set of codes thus it's important to consult the relevant guidelines for accurate information.
Step-by-step explanation:
The proficiency codes used to identify subject knowledge are typically specific to the context in which they are used and may vary by institution, organization, or specific testing system. Therefore, without additional context, it is not possible to definitively say which codes are correct among the options provided (P1, P2, P3; A1, A2, A3; K1, K2, K3; S1, S2, S3). It is important to refer to the applicable guidelines or standards provided by the educational or testing authority in question.
In the context of education and assessment, such proficiency codes are used to categorize or rank a student's understanding or competency in a subject area. For instance, 'A+' might signify excellence, while 'P1' or 'K1' might indicate a foundational level of knowledge or ability.