Which of the following statements can neither be both true, nor can they both be together false?

Which of the following propositions are so related that they cannot both be true although they may both be false? A. All cars are vehicles. B. Some cars are vehicles. C. No cars are vehicles. D. Some cars are not vehicles. Choose the correct answer from the options given below:

Given below are two statements: Statement A: 'All physicians whose licenses have been revoked are physicians ineligible to practice.' Statement B: 'All physicians eligible to practice are physicians whose licenses are intact.' Which of the following is true with regard to the above two statements?