You are given a mathematical question described with a circumscribed mathematical vocabulary. Questions in this task usually contain some variables (e.g. X, Y), equations (e.g. X+Y=3) and some relationships (X is greater than Y). Often you need to find the value of the variable using equations and relationships. You are also given 4 or 5 answer options (associated with "A", "B", "C", "D", "E"). Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D', 'E'. LaTeX mathematical format (the standard way to express mathematical expressions in the typesetting software known as LaTeX) is used to express equations. Each question is solvable with high school math knowledge. Give only one answer for each question.

[Q]: If \(\frac{a}{b} = 4\), \(a = 8c\), and \(c = 9\), what is the value of b?
(A)2 (B)8 (C)18 (D)36 (E)72
[A]: C


[Q]: If \(x > 0\) and 20 percent of \(x\) is 30 percent of\( y\) , which of the following represents 80 percent of \(x\) ?
(A)\(0.5y\) (B)\(0.8y\) (C)\(0.9y\) (D)\(y\) (E)\(1.2y\)
[A]: E


[Q]: If the members of set A are all the odd single-digit positive integers and the members of set B are all the prime integers, which of the following is the set of numbers common to both set A and set B ?
(A)\(\lbrace 1, 3, 5, 7\rbrace\) (B)\(\lbrace 1, 3, 5, 7, 9\rbrace\) (C)\(\lbrace 2, 3, 5, 7\rbrace\) (D)\(\lbrace 3, 5, 7\rbrace\) (E)\(\lbrace 3, 5, 7, 9\rbrace\)
[A]:
D