using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"^\(\d+\) (.+)\n(\([A-Z]\).*?)। Ans \(([A-Z])\)";
string input = @"(1) Capital of Bangladesh is-
(A) Dhaka (B) Rangpur (C) Chittagong (D) Comilla। Ans (A) Dhaka
(2) Largest city of Bangladesh is-
(A) Mirpur (B) Rangpur (C) Chittagong (D) Comilla। Ans (C) Chittagong
(3) Smallest city of Bangladesh is-
(A) Dhaka (B) Rangpur (C) Chittagong (D) Meherpur। Ans (B) Rangpur";
RegexOptions options = RegexOptions.Multiline;
foreach (Match m in Regex.Matches(input, pattern, options))
{
Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index);
}
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx