You are making the field describe call on:

... Business_Unit__c.name ...

which is not a picklist field and so will return a zero length array of PicklistEntry which in turn will result in no select list options.

Use the API name of your picklist field:

DescribeFieldResult result = Business_Unit__c.ApiNameOfPicklistField__c.getDescribe();

Note that this is an answer to an earlier version of the question.

You are making the field describe call on:

... Business_Unit__c.name ...

which is not a picklist field and so will return a zero length array of PicklistEntry which in turn will result in no select list options.

Use the API name of your picklist field:

DescribeFieldResult result = Business_Unit__c.ApiNameOfPicklistField__c.getDescribe();