Which of the following is a carbohydrate?

What is the value of specific rotation exhibited by glucose molecule?

Select the correct statement among the following:

Glucose and gluconic acid on oxidation with dilute nitric acid $(HNO_3)$ form saccharic acid. This reaction confirms that glucose contains:

Four carbohydrates: glucose,lactose,sucrose,and starch are present. Different tests are carried out with these $4$ carbohydrates separately. The following observations are made:
$(a)$ Heated: It is charred.
$(b)$ $I_2$ solution: No violet colour.
$(c)$ Fehling solution: Reddish brown precipitate is observed.
$(d)$ It does not reduce copper$(II)$ acetate to $Cu_2O$. No red precipitate is observed in $5 \ min$.
Which carbohydrate satisfies all the above observations?

Only two carbon atoms of glucose participate in the formation of osazone because they undergo .......