Sugar extracted from the roots of Dahelia and other tuberous plants
Inulin is a type of sugar that is extracted from the roots of Dahelia and other tuberous plants. It is a polysaccharide, meaning it is made up of multiple sugar molecules bonded together. Inulin is primarily found in the roots and rhizomes of these plants, where it serves as a storage carbohydrate.

Useful in the determination of Glomerular filtration rate of kidneys
The glomerular filtration rate (GFR) is a measure of how well the kidneys are functioning. It is an important indicator of kidney health and can help diagnose and monitor conditions such as chronic kidney disease. Inulin is commonly used in medical settings to measure GFR.

When inulin is injected into the bloodstream, it is freely filtered by the glomerulus, the tiny blood vessels in the kidneys. It is not reabsorbed or secreted by the renal tubules, making it an ideal substance for measuring GFR. By measuring the concentration of inulin in the urine over a certain period of time, healthcare professionals can calculate the GFR.

Comparison to other options
a) Trehalose: Trehalose is a disaccharide sugar composed of two glucose molecules. It is not extracted from the roots of Dahelia or tuberous plants, so it is not the correct answer for this question.

b) Vervascose: Vervascose, also known as raffinose, is a trisaccharide sugar composed of glucose, fructose, and galactose. Like trehalose, it is not extracted from the roots of Dahelia or tuberous plants, so it is not the correct answer.

Correct answer: Inulin
c) Inulin: Inulin is a polysaccharide sugar that is indeed extracted from the roots of Dahelia and other tuberous plants. It is commonly used in the determination of glomerular filtration rate (GFR) of the kidneys. Inulin is freely filtered by the glomerulus and not reabsorbed or secreted by the renal tubules, making it an ideal substance for measuring GFR.

d) Gentibiose: Gentibiose is a disaccharide sugar composed of two glucose molecules. It is not extracted from the roots of Dahelia or tuberous plants, so it is not the correct answer for this question.