Which of the following has highest solubility in water? Which of the following has highest solubility in water?

A. $ Ca(OH)_2 $

B. $ Fe(OH)_3 $

C. $ Cr(OH)_3 $

D. $ Zn(OH)_2 $

And also please explain how can we predict their solubilities when we are not provided with their solubility products.

I know that calcium hydroxide is sparingly soluble. So it cannot be the right option. I think Iron hydroxide is also soluble to a good extent. I haven't got any idea about option C. I think D may be the right answer.
You can't predict solubility reasoning, you have to remember solubility rules in your case this one:


  
  Most hydroxide salts are only slightly soluble. Hydroxide salts of Group I elements are soluble. Hydroxide salts of Group II elements (Ca, Sr, and Ba) are slightly soluble. Hydroxide salts of transition metals and $\ce{Al^3+}$ are insoluble. Thus, $\ce{Fe(OH)3, Al(OH)3, Co(OH)2}$ are not soluble. 
  


So in this case $\ce{Ca(OH)2}$ even if slightly soluble theoretically should be the right answer.