title: Retrieve all OptionSet values using OData in Dynamics CRM
body: <p>I am quite new to Dynamics CRM. I am building an app which should update entity in Dynamics CRM. I can update simple types without any issues. Now the situation is, I have declared some custom Option Sets in Contact entity. </p>
  
  <p>Is there any way to retrieve all the possible OptionSet values (text and value) so that my app can look for appropriate value and set it in the payload it is generating? </p>
  
  <p>I can not find any endpoint in <code>WebAPI</code> as well as <code>XRMServices/2011/OrganizationData.svc</code>. Any help would be really awesome. </p>