The answer would be : a convention.
Hope this helps !
Photon
The difference for the given polynomial is 
Explanation:
The given polynomial is 
A polynomial is generally a sum or difference of terms or variables which are separated by addition and subtraction signs. There are "three types of polynomial": Monomial, binomial and trinomial.
The difference between is found as follows:
D = 
Removing the brackets, we get,
D = 
D = 
D = 
Thus, the polynomial represents Option A as the difference.
E. defend their actions through an advocate
Civil rights
coercion during 60s was at its peak most especially in the issue of the coercion
and discrimination of the black Americans from the whites. The struggle of
racial inequality amongst black Americans which lead to the emergence of the
Civil Rights Movement lead by Martin Luther King where truly the impetus of the
strengthened Civil Rights Law. Through this advocate all other human rights
began to be galvanized in the world.