在.NET中格式化字符串的正确位置在哪里？

string formattedString = String.Format("Hello, {0}! Today is {1:MM/dd/yyyy}.", name, DateTime.Now);

StringBuilder sb = new StringBuilder();
sb.AppendFormat("Hello, {0}! Today is {1:MM/dd/yyyy}.", name, DateTime.Now);
string formattedString = sb.ToString();

string formattedString = $"Hello, {name}! Today is {DateTime.Now:MM/dd/yyyy}.";

string formattedString = String.Format("Hello, {0}! Today is {1:MM/dd/yyyy}.", name, DateTime.Now.ToString("MM/dd/yyyy"));