To solve this problem, we need to identify which hydroxide is amphoteric.$\newline$An amphoteric hydroxide can react with both acids and bases.$\newline$Let's analyze each option:$\newline$• Option 1: $Sr(OH)_2$ is a strong base and not amphoteric.$\newline$• Option 2: $Ca(OH)_2$ is also a strong base and not amphoteric.$\newline$• Option 3: $Mg(OH)_2$ is a weak base but not typically amphoteric.$\newline$• Option 4: $Be(OH)_2$ is amphoteric. It can react with acids to form $Be^{2+}$ ions and with bases to form $BeO_2^{2-}$ ions.$\newline$Therefore, the correct option is Option 4: $Be(OH)_2.$