Please choose the correct solution to the question: Make a marker in your garage to know when to stop backing up

Solution1: Using a string, a long tack and brick, attach the tack to the brick and then attach the string to the tack and to ceiling of your garage. Experiment to find the right parking location in your garage.

Solution2: Using a string, a long tack and tennis ball, attach the tack to the tennis ball and then attach the string to the tack and to ceiling of your garage. Experiment to find the right parking location in your garage.

Answer format: solution1/solution2
Answer: solution2