Which of the following statements are true ?(A) A sentence α entails another sentence β if β is true in few worlds where α is true.(B) Forward chaining and backward chaining are very natural reasoning algorithms for knowledge bases in Horn form.(C) Sound inference algorithms derive all sentences that are entailed.(D) Propositional logic does not scale to environments of unbounded size.Choose the correct answer from the options given below:

• A. (A) and (B) only
• B. (B) and (C) only
• C. (C) and (D) only
• D. (B) and (D) only