Exp) Option c is the correct answer.

The Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family, are a large and agriculturally important family of flowering plants.

Option 1 is correct. The ground nut belongs to the pea and bean family and is a legume. The groundnut is the only nut that grows below the earth.

Option 2 is correct. Horsegram belongs to family Fabaceae or pea is a potential grain legume having excellent nutritional and remedial properties with better climate resilience to adapt harsh environmental conditions.

Option 3 is correct. Soybean is a flowering plant (angiosperm) and is a dicot (eudicot) , in the Fabaceae, the pea family.

Source: https://agriexchange.apeda.gov.in/product_profile/prd_profile.aspx?categorycode=0501#:~:text=The%20groundnut%20belongs%20to%20the,in%20height.

https://www.cabidigitallibrary.org/doi/pdf/10.5555/20153340308

https://milnepublishing.geneseo.edu/botany/chapter/soybeans-and-other-beans/#:~:text=Soybean%20is%20a%20flowering%20plant,species%20that%20are%20important%20ecologically.