Answer:
d. conjugate base.
Step-by-step explanation:
Conjugate base -
As , a proton is removed from an acid , it lead to the formation of a conjugate base .
For example ,
Consider an acid HA , the proton is lost from the acid in the following way -
HA --------> H⁺ + A⁻
H⁺ is the proton lost
And ,
A⁻ is the conjugate base .
Hence , from the given option of the statement , the correct term is d. conjugate base .