Answer: b. HSO4-
Explanation:
H2SO4 (sulfuric acid) will donate a hydrogen ion in solution to form H3O+(hydronium). The remaining HSO4- would be the conjugate base of this dissociation.
A conjugate base contains one less H atom and one more - charge than the acid that formed it.
A conjugate acid contains one more H atom and one more + charge than the base that formed it.