Final answer:
Games like Call of Duty and Grand Theft Auto are 'franchise titles' due to their expansive, recurring series with multiple titles that achieve sustained popularity and success.
Step-by-step explanation:
The term 'franchise titles' in the context of games like Call of Duty and Grand Theft Auto refers to option C, which is 'Their expansive, recurring series with multiple titles.' These franchise titles are multi-game series that have enjoyed sustained popularity and sales over the years, thereby establishing themselves as staples in the gaming industry. Such games are known for providing a combination of engaging gameplay, multi-player experiences, and, at times, controversial content. In the case of Grand Theft Auto, its frequent focus on gratuitous violence has led to debates concerning its influence within the gaming community.