Suppose the following logical relational data model having one universal relation in 1st normal form: Car(V incode, Model, Colour, Engine, Doors)

All attributes are functionally dependent on V incode attribute (i. e. the V incode is the (only) key of the relation). Moreover, the attribute Doors is functionally dependent on attribute Model (ie. two cars of the same model have to necesarilly have the same number of doors).

a. Is the above relation in 2nd normal form?
b. Is the above relation in 3rd normal form? Why?
c. If not, how the logical relational model should be changed to achieve at least the 3rd normal form?