Consider the following statements regarding a Grillage Foundation:
1. It is provided for heavily loaded isolated columns.
2. It is treated as a spread foundation.
3. It consists of two sets of perpendicularly placed steel columns.
Which of the above statements are correct?
1. 1 and 2 only
2. 1 and 3 only
3. 2 and 3 only
4. 1, 2 and 3