The correct answer is option 1, which states that statement 1 is correct.

To further explain, the Harappa Civilization, also known as the Indus Valley Civilization, was a Bronze Age civilization that existed around 2600-1900 BCE in the northwest region of the Indian subcontinent. The civilization is known for its advanced urban planning, sophisticated drainage systems, and a standardized system of weights and measures.

Statement 1 is correct because there is indeed uniformity in artifacts found from the Harappa sites. Archaeological excavations have revealed a high degree of consistency in pottery, seals, bricks, and weights across various Harappa sites. This uniformity suggests a centralized authority or a common cultural identity throughout the civilization.

However, statement 2 is incorrect. The late Harappa sites, which refer to the later phase of the civilization, did not maintain the same construction techniques as the mature Harappa sites. The late Harappa sites show a decline in urban planning and a lack of well-constructed buildings compared to the earlier phase.

In conclusion, statement 1 is correct, but statement 2 is incorrect.