Answer:
O Ca(OH)2
Step-by-step explanation:
According to Arrhenius definition of a base, it is a substance that dissociates in water to form hydroxide ions (OH-). This means that in the neutralization reaction between calcium hydroxide and sulfuric acid as described in this question, calcium hydroxide is the base because it contains the hydroxide ion (OH-).
Calcium hydroxide is a combination of calcium (Ca2+) as the cation and hydroxide (OH-) as the anion. Hence, the chemical formula will be Ca(OH)2.