Step 1: Understanding the Concept
Proteins are grouped by shape. Fibrous proteins form long threads and are insoluble in water. Globular proteins fold into a compact spherical form and dissolve in water.
Step 2: About Legumelin
Legumelin is an albumin-type protein present in legumes such as peas and beans. Albumins are water-soluble globular proteins.
Step 3: Check the options
(A) It is not a carbohydrate. (C) Fibrous proteins include keratin and myosin, which are not water-soluble. (D) Although many enzymes are globular proteins, Legumelin is classed as a storage protein and not as an enzyme. So (B) globular protein is the best description.
Final Answer:
Legumelin is a water-soluble albumin, so it is a globular protein, option (B).
\[ \boxed{\text{Globular protein}} \]