In which of the following disaccharides both the basic structural units are the same?

In which of the following disaccharides both the basic structural units are the same?

مندرجہ ذیل میں سے کس میں دونوں بنیادی ساختی اکائیوں ایک جیسے ہیں؟
Explanation

Maltose is made of two glucose molecules, so both structural units are the same.

Lactose = glucose + galactose (different units).

Sucrose = glucose + fructose (different units).