Detailed Explanation:

Correct Answer: ✅ Option 3 (All Three)

All three plants—Groundnut, Horse-gram, and Soybean—belong to the Fabaceae (also called Leguminosae or pea family). Members of this family typically produce fruits in the form of pods (legumes) and possess nitrogen-fixing root nodules.

✅ Groundnut (Arachis hypogaea) – Correct: Belongs to the Fabaceae family and produces seeds inside pods.

✅ Horse-gram (Macrotyloma uniflorum) – Correct: A leguminous crop belonging to the pea family.

✅ Soybean (Glycine max) – Correct: One of the world's most important legumes and a member of Fabaceae.

Therefore, all three belong to the pea family.

Short Notes: Fabaceae (Pea Family)

• One of the largest flowering plant families with over 19,000 species.

• Also known as Leguminosae.

• Characterized by pod-like fruits (legumes).

• Roots contain Rhizobium bacteria that fix atmospheric nitrogen.

• Important food crops include pea, gram, lentil, soybean, groundnut, and horse-gram.

• Helps improve soil fertility through nitrogen fixation.

• Rich source of protein in human and animal diets.

• Economically important for food, fodder, oil, and soil conservation.