In the kernel density estimator context, the contribution of a single kernel centered at x_i to the pdf is proportional to which expression?

In the kernel density estimator context, the contribution of a single kernel centered at x_i to the pdf is proportional to which expression?

• A. exp(-(x - x_i)^2 / (2 * bandwidth^2))
• B. bandwidth
• C. x_i
• D. 1

Answer: (A)