Question from the Typescript - Overview test

namespace utils {
 export class Logger {
 log(message: string): void {
 console.log(message);
 }
 }
}

module utils {
 class Logger {
 log(message: string): void {
 console.log(message);
 }
 }
}

export module utils {
 export class Logger {
 log(message: string): void {
 console.log(message);
 }
 }
}