Correct option is A
The exterior walls of the building have several cracks, which should be repaired before the painting of the walls begins, so that later there is no problem with leakage.
The statement mentions that cracks in the walls should be repaired before painting to avoid future leakage problems. However, it does not explicitly state that painting itself causes leakage problems, but that the cracks need repair before painting to prevent leakage.
Therefore, Conclusion I is not directly implied.
Conclusion II: Cracks in the exterior walls can cause leakage problems.
The statement clearly indicates that the cracks in the exterior walls need to be repaired to prevent leakage. This directly implies that the cracks are a potential cause of leakage problems.
Therefore, Conclusion II is implied.