The correct answer is option 4: Moist deciduous tree.

The ‘Sal’ tree is a type of tree that is classified as a moist deciduous tree. This means that it sheds its leaves during a specific season, usually during dry periods, and regrows them when there is sufficient moisture available. Moist deciduous trees are commonly found in regions with seasonal rainfall patterns.

Option 1: The Sal tree is not a tropical evergreen tree, which are trees that retain their leaves all year round in tropical regions.

Option 2: The Sal tree is not a tropical semi-evergreen tree either, which are trees that retain some of their leaves throughout the year in tropical regions.

Option 3: The Sal tree is also not a dry deciduous tree, which are trees that shed their leaves during dry seasons or droughts.

Therefore, the correct classification for the Sal tree is a moist deciduous tree.

Note: It is important to correctly identify the characteristics of different types of trees to better understand their behavior and adaptability in different environments.