To an aqueous solution containing ions such as Al³⁺, Zn²⁺, Ca²⁺, Fe³⁺, Ni²⁺, Ba²⁺ and Cu²⁺ was added conc. HCl, followed by H₂S.

The total number of cations precipitated during this reaction is/are :

Compound A gives D-Galactose and D-Glucose on hydrolysis. The compound A is :

$$R - CN\mathrel{\mathop{\kern0pt\longrightarrow} \limits_{(ii){H_2}O}^{(i)DIBAL - H}} R - Y$$

Consider the above reaction and identify "Y"

Consider the above reaction, and choose the correct statement :