Which of the following is TRUE about backpropagation? $($Select all that apply$)$

a$.$ Backpropagation corresponds to updating the parameters of a neural network

using gradient descent.

b$.$ Backpropagation involves adding weights for minimizing an objective function

for more effective training of the network

c$.$ Backpropagation involves computing the partial derivatives of an objective

function with respect to the weights of the network.

d$.$ Backpropagation computes partial derivatives starting from the first layer in the

network, to save computation