Complete the series: z, x, v, t, ?

A. R

In a family of six members A, B, C, D, E, and F, A is the father of B. C is the mother of B and D. E is the sister of B. F is the brother of D. How is E related to F?

A. SISTER

A is married to B. They have two children, C and D. C is a doctor and D is a lawyer. If B is a teacher, what is A's profession if he is not in the same profession as B?

B. ENGINEER

In a code, 'APPLE' is represented as '1-16-16-12-5'. What is the code for 'GRAPE'?

A. 7-18-1-16-5

In a coded system, 'CLOUD' is coded as '45678', 'SHINE' is coded as '12345', and 'MIND' is coded as '6789'. What is the code for 'DUNE'?

D. 6785