Which of the following is true about the Information Retrieval system?

(a) Classical IR Model: It emphasizes document representation, query representation, and retrieval/matching function.

(b) Non-Classical IR Model: these are built upon propositional logic and include models like Information Logic and Interaction models.

(c). Alternative IR Model: These models enhance Non-classical IR principles

(d). Vector Space Model: Documents and queries are represented as vectors, and documents are retrieved based on similarity.