How would you connect the truck cabin to the semi-trailer?

1. By driving backwards at an angle of less than 15 degrees.
2. By pushing the semi-trailer forward until the truck cabin.
3. Correct answer: By driving backwards when both of them are aligned in a straight line.
4. By driving backwards while the cabin is in a diagonal angle or any other comfortable angle..

WhyA semi-trailer is hitched by backing the cab up to it when both are aligned in a straight line.