When the Following Equations Are Balanced Using the Smallest Possible $\rightarrow$

When the following equations are balanced using the smallest possible integers, what is the number in front of the underlined substance in each case?
-Al₂O₃(s) + H₂SO₄(aq) $\rightarrow$ Al₂(SO₄) ₃(aq) + H₂O(l)

A) 1
B) 2
C) 3
D) 6
E) 9