1. Aus: Aus rice is one of the major types of rice cultivated in West Bengal. It is a short-duration, drought-tolerant rice variety, typically grown during the summer season, primarily in lowland areas with the onset of the monsoon. 

2. Aman: Aman rice is another prominent rice variety in West Bengal. It is a monsoon crop and is sown with the arrival of the southwest monsoon. Aman rice is usually transplanted during June and July and harvested in the post-monsoon period, typically from November to December. It is a staple food crop for the region.

3. Boro: Boro rice is the third significant rice variety in West Bengal. It is a winter crop, grown during the dry, cool season. Boro rice is transplanted in December and January and harvested in April and May. This variety is known for its high yield potential and is often grown with irrigation.

4. Zaid: "Zaid" is not a type of rice but rather refers to a cropping season that falls between the Kharif (monsoon) and Rabi (winter) seasons. It typically includes the cultivation of crops like vegetables, fruits, and other secondary crops during the summer months when temperatures are relatively high. 

So, option 2 is correct.