Final answer:
The statement is true; William of Orange was married to James II's daughter Mary and was in line for the throne of England, which he eventually ascended to jointly with Mary after the Glorious Revolution.
Step-by-step explanation:
The statement about William of Orange being married to James II's daughter, Mary, and also being in line for the throne of England is true. When James II was deposed during the Glorious Revolution, William and Mary were invited by the Parliament to rule jointly in what is known as 'The Crown' being offered to them. This event marked William of Orange's ascension to the English throne, which was not just by right of his marriage to Mary but through the invitation of the English Parliament due to the constitutional crisis of the time.