Final answer:
None of the lines contain an error.
Step-by-step explanation:
The line containing an error is Line 2: 2 = 7h - 12.
To identify the error, we need to check if the equation is true for all values of h. Substituting h=2 into Line 2, we get 2 = 7(2) - 12, which simplifies to 2 = 14 - 12, and further simplifies to 2 = 2. This equation is true. Therefore, the error lies in the question itself where it asks which line contains an error.
The correct answer should be: None of the lines contain an error.