Which of the following statement(s) is/are true about activation functions? (1) The activation functions are used to define the output of a node given the input. (2) The sigmoid function can be used...

Which of the following statement(s) is/are true about activation functions?

(1) The activation functions are used to define the output of a node given the input.

(2) The sigmoid function can be used as an activation function.

(3) It always works as a linear function.

(4) It is a parameter that is optimized during backpropagation.

A. (1), (2) & (3)

B. (1) & (2)

C. (3) & (4)

D. (1) & (3)