Can someone please help ​

C

Step-by-step explanation:

We can use the pythagorean theorem (A^2 + B^2 = C^2) To solve this question.

For answer A, we add 6^2 (36) and 8^2(64) to get 10^2 (100). This is a right triangle.

For question B, we add ^2 (3) and ^2 (8) to get . This is a right triangle.

For question C, we add 3^2 and 5^2 to get . This is not a right triangle.

answer:

1. at 1 month, $5 is spent.

2. at 0 months, $0 is spent.

3. at 4 months, $20 is spent.