Final answer:
The most likely litigation related to taking a patient's photograph without consent is invasion of privacy, not assault and battery, slander, or libel which involve different elements, such as physical contact or false statements.
Step-by-step explanation:
The most likely type of litigation involving photography of a patient without valid consent is b. Invasion of privacy. This is because unauthorized photography of a patient may disclose their private matters without permission and is not directly related to any physical contact as would be the case in assault and battery, nor does it inherently involve the communication of false statements as in slander or libel. In the context of slander and libel, it is essential to understand that they involve the presentation of false information as factual and require different standards of proof based on whether the plaintiff is a private or public figure, as established in the New York Times v. Sullivan (1964) case.