B is a good question because by asking this question the person who is taking the interview can find about the potential qualities of the employee. In this way he or she can also judge his/her personality and interests which can lead that person taking interview choose the best work for the employee. So B is good question.
D is also good question because in this question a person can know all about the reason behind the establishment of a company doing work in the market.
By asking this question a person can know about the goal and aims of the company and also the benefits which the company provides to its employees and also to the community around it or using its products or services. So, asking the company's mission statement is a very good question in an informational interview.
