(a) the spouse; (b) the partner with whom the Union citizen has contracted a registered partnership, on the basis of the legislation of a Member State, if the legislation of the host Member State treats registered partnerships as equivalent to marriage and in accordance with the conditions laid down in the relevant legislation of the host Member State; (c) the direct descendants who are under the age of 21 or are dependants and those of the spouse or partner as defined in point (b); (d) the dependent direct relatives in the ascending line and those of the spouse or partner as defined in point (b).