Answer: B
Step-by-step explanation:
This looks like a cosine function. Cosine can take on any x value and still be defined. That means all real numbers will work. When asked for domain, it really just means what x values are defined for this function. We just said, cosine can take any x value
If you didnt know this was a cosine function, you could just visually see the function goes on to -∞ and +∞. There's no reason for the function to run into a critical point
