Five friends, P, Q, R, S, and T, are standing in a line. P is taller than Q but shorter than R. S is shorter than T but taller than Q. Who is the tallest?

B. R

In a group of students, X scored more than Y but less than Z. W scored less than X but more than Y. Who scored the least?

B. Y

Among A, B, C, and D, A is older than B but younger than C. D is younger than A. Who is the youngest?

D. D

In a competition, M scored higher than N but lower than O. P scored lower than M but higher than N. Who has the highest score?

C. O

Four friends - A, B, C, and D - have different pets: a dog, a cat, a bird, and a fish. A does not have a dog. B has a cat. C does not have a fish. Who has the dog?

D. D