Which of the following statements about Mohenjo-Daro is correct?

a. Gold ornaments were unknown.
b. Houses were made of burnt bricks.
c. Implements were made of iron.
d. Great Bath was made water tight with the layers of natural bitumen

Consider the following statements: 
1. Uniformity in layout of town, streets, and brick sizes
2. An elaborate and well laid out drainage system
3. Granaries constituted an important part of Harappan Cities

Which of the above statements are correct?