An essay that is a sound interpretation of text, supported by evidence drawn from the readings, well organized with few grammatical errors, none of which interfere with comprehension, will normally receive a B grade You are being asked to write theoretical essays. In general, a theory is a generalized statement linking variables.
Theories come in many shapes and forms.
There is normative theory, descriptive theory, analytic theory, causal theory, critical theory and so forth. But a common element of theory is its generality. You should think of theory as a big idea that can apply to many specific situations. For example, some of our earlier readings talk about the struggles of welfare recipients. The focus of your essay should always be on these larger, more abstract, concepts that you find in the various texts, e.g., The Constitution of Liberty.