In such type of questions, clues are given regarding comparisons among a set of persons or things with respect to one or more qualities. The candidate is required to analyse the whole information, form a proper ascending / descending sequence and then answer the given questions accordingly.
There are five friends --- Sachin, Kunal, Mohit, Anuj and Rohan.
Sachin is shorter than Kunal but taller than Rohan.
Mohit is the tallest.
Anuj is a little shorter than Kunal and little taller than Sachin.
Who is the shortest ?
Let us denote the five boys by the first letter of their names, namely S, K, M A and R.
R < S < K < M and S < A < K.
R < S < A < K < M.
Rohan is shortest. So, the answer is (a).