ANSWER:
1st option: 126
STEP-BY-STEP EXPLANATION:
In this case, we must select from 4 toppings out of 9 that are in total. Since the order of toppings doesn't matter, it would be a combination of 4 in 9.
Therefore, we apply the combination formula that is as follows:
[tex]\begin{gathered} nCr=\frac{n!}{r!\left(n-r\right)!} \\ \\ n=9,r=4 \\ \\ \text{ We replacing:} \\ \\ _9C_4=\frac{9!}{4!\cdot(9-4)!} \\ \\ _9C_4=\frac{9!}{4!\cdot5!}=126 \end{gathered}[/tex]
Therefore, the correct option is 1st option: 126
