Which of the following statements is true about simple carbohydrates:

A. Disaccharides are composed of two simple sugars

B. Sucrose is a common monosaccharide found in sugar cane and beets

C. Glucose is a common disaccharide found in all plants

D. Monosaccharides are composed of two or more sugar molecules

The answer is A, disaccharides are compose of two simple sugars.

Dissacharide is formed when 2 monosaccharides reacts in the condensation reaction, they produce a Dissacharide and a water molecule during the reaction.

B is not correct because sucrose is a disaccharide. C is also not correct because glucose is a monosaccharide. And last but not least, d is not correct too because monosaccharide is the simplest form of sugar.

Thereofre, the correct answer is a.