Select the evidence for the open chain structure of glucose.

For 'invert sugar',the correct statement$(s)$ is(are)
(Given: specific rotations of $(+)$-sucrose,$(+)$-maltose,$L-(-)$-glucose and $(+)$-fructose in aqueous solution are $+66^{\circ}, +140^{\circ}, -52^{\circ}$ and $+92^{\circ}$,respectively)
$(A)$ 'invert sugar' is prepared by acid catalyzed hydrolysis of maltose
$(B)$ 'invert sugar' is an equimolar mixture of $D-(+)$-glucose and $D-(-)$-fructose
$(C)$ specific rotation of 'invert sugar' is $-20^{\circ}$
$(D)$ on reaction with $Br_2$ water,'invert sugar' forms saccharic acid as one of the products

Fructose on reduction gives a mixture of two alcohols which are related as

Which reaction proves that all the six carbon atoms are linked in a straight chain in glucose?

Raffinose is

Molisch's test is done for the detection of