No quite sure what you are trying to achieve with <option data-bind="text: Value, attr: { value: Value }"></option>.
Have a look at my fiddle for a few different setups. It contains usages of both options and foreach bindings on a select element.
To answer the question, you provide a function in your viewModel to provide the desired data. As long as your viewModel can "access" the data, the function will provide it to the binding. If the data were to be a simple list of literals, then all that is required :
Javascript:
var listOfLiterals = function() { return ["One", "Two", "Three"] };
var viewModel = {
selectedLiteral: ko.observable(),
getLiterals: function() {
return listOfLiterals();
}
}
HTML:
<select data-bind="options: getLiterals(), value: selectedLiteral"></select>