Dass, Landless and women were considered the lowest class jn the Varna system, who were to serve all the upper 3 classes and worked as Agriculturalists in the Later Vedic era.

Agriculture was one of the major occupations in ancient India, and the farmers were an integral part of the agriculture field. The farmers belonged to different sections of society based on their caste and gender. Let's discuss the options given in the question.

Option A: Dass, Landless people, Women
- Dass: The Dass were a community of landless laborers who worked for the landowners in exchange for wages or a share of the crop. They were considered the lowest in the social hierarchy and were often exploited by the landlords.
- Landless people: There were many landless people who worked as laborers in the fields. They did not own any land and worked for wages.
- Women: Women also worked in agriculture, especially in tasks like sowing, weeding, and harvesting. They were not given equal status as men and were often paid less for the same work.

Option B: King, Purohit, Women
- King: The kings were not directly involved in farming. However, they owned large tracts of land and had control over the agricultural activities in their kingdom.
- Purohit: The Purohit or the priest was responsible for performing religious ceremonies and rituals. They did not work in agriculture.
- Women: As mentioned earlier, women did work in agriculture, but they were not the only ones.

Option C: Dass, Shudras, Vaishyas
- Dass: As explained earlier, the Dass were a community of landless laborers who worked in agriculture.
- Shudras: The Shudras were considered the fourth in the social hierarchy and were mainly engaged in manual labor. Many Shudras worked as farmers or laborers in agriculture.
- Vaishyas: The Vaishyas were the trading and merchant class, but they also owned land and were involved in agriculture.

Option D: Dass, Brahmins, Kshatriyas
- Dass: As explained earlier, the Dass were a community of landless laborers who worked in agriculture.
- Brahmins: The Brahmins were the priestly class and were not directly involved in agriculture.
- Kshatriyas: The Kshatriyas were the warrior class and were mainly engaged in military activities. They owned land but were not directly involved in agriculture.

Therefore, option A is the correct answer as it includes the groups of people who were directly involved in agriculture - the Dass who were landless laborers, landless people who worked for wages, and women who worked in the fields.