Final answer:
The correct set notation to represent a domain containing all positive integers is x , which corresponds to option A.
Step-by-step explanation:
The domain of a function that includes all positive integers can be represented using set notation as x . Hence, the correct option is A. This notation effectively communicates that the function's domain consists of all numbers that are positive integers (1, 2, 3, ...).
It's important to understand set notation as it's a fundamental aspect of defining functions and their domains in mathematics, particularly in topics such as probability distribution functions (PDFs) for discrete random variables.