Which of the following is a non-reducing disaccharide sugar?

Hydrolysis of sucrose is called

$L$-isomer of tetrose $X$ $(C_4H_8O_4)$ gives positive Schiff's test and has two chiral carbons. On acetylation,$X$ yields triacetate. $X$ also undergoes the following reactions:
$X$ $\xrightarrow{HNO_3} A$ $\xrightarrow{NaBH_4} \underset{\text{Chiral compound}}{B}$
$X$ is $.......$.

Which of the following statements is $NOT$ correct?

Number of stereo centers present in linear and cyclic structures of glucose are respectively

The number of atoms in the cyclic structure of $D$-fructose is