In a class of 80 students, a student is to be selected for becoming monitor. If 20 % of total students belongs to ST category, 15 % belongs to SC category, 30 % belongs to OBC category and remaining belongs to General category and in each category the ratio of boys and girls is 1 : 1. What is the probability that the monitor selected is a girl who belongs to either ST or OBC category ? A. \(\frac {3} {5}\) B \(\frac{1}{4}\). C \(\frac{3}{4}\). D. \(\frac{3}{8}\) E. None of these