The correct answer is option 1: 4-2-3-1.

To better understand the arrangement of these treaties/conventions, let`s analyze each option:

Option 1: 4-2-3-1

This option suggests that the Treaty of Surat was signed first, followed by the Treaty of Purandar, then the Convention of Wadgaon, and finally the Treaty of Salbai.

Option 2: 4-3-2-1

This option suggests that the Treaty of Surat was signed first, followed by the Convention of Wadgaon, then the Treaty of Purandar, and finally the Treaty of Salbai.

Option 3: 1-3-2-4

This option suggests that the Treaty of Salbai was signed first, followed by the Convention of Wadgaon, then the Treaty of Purandar, and finally the Treaty of Surat.

Option 4: 1-2-3-4

This option suggests that the Treaty of Salbai was signed first, followed by the Treaty of Purandar, then the Convention of Wadgaon, and finally the Treaty of Surat.

Based on the correct answer provided, option 1 is the correct arrangement