Which for the following is considered a weak base? A. Lithium hydroxide B. Sodium hydroxide C. Calcium hydroxide D. Aluminum hydroxide Thanks!

Well $D .$ is probably the best answer....
We gots $A l {\left(O H\right)}_{3}$...even tho this is still a basic species. $\text{Alumina}$, $A {l}_{2} {O}_{3}$, is an amphoteric oxide...that could act as an acid. The hydroxides of lithium, calcium, or sodium, all give rise to basic solutions....