The most common disaccharide has the molecular formula:

Disaccharides are the carbohydrates which on hydrolysis gives two same or different carbohydrates.

Sucrose is the most common disaccharide.

It can be found in many fruits and is naturally occuring. 

It has molecular formula ${\mathrm{C}}_{12}{\mathrm{H}}_{22}{\mathrm{O}}_{11}$.Option D is correct.