(25 points and brainliest) given the system of equations presented here:

4x + y = 4
2x + 7y = 28

which of the following actions creates an equivalent system such that, when combined with the other equation, one of the variables is eliminated?

a. multiply the second equation by −1 to get −2x − 7y = −28
b. multiply the second equation by −4 to get −8x − 28y = −112
c. multiply the first equation by −7 to get −28x − 7y = −28
d. multiply the first equation by −2 to get −8x − 2y = −8