Step 1: Understanding image resolution.
Image resolution refers to the amount of detail an image holds, which depends on the number of pixels used to form the image.
Step 2: Evaluating options.
• (A): Refers to pixel intensity, not resolution.
• (B): Correct. More pixels mean higher resolution and better detail.
• (C): File size depends on compression and format.
• (D): Not related to resolution.
Step 3: Conclusion.
Thus, resolution is determined by the number of pixels in the image.
Final Answer: The number of pixels in the image.