Stella divided 12/8.
If we divide 12 by 8, we get exactly 1.5.
Let us check given options one by one .
A) Stella made an error : Stella didn't made an error because it's just division of two numbers.
B) The answer is exactly 1.5. : On dividing 12 by 8, we get exactly 1.5, so this option is correct.
C) The calculator rounded the answer. : On dividing 12 by 8, we get exactly 1.5. So, no rounding is required.
D) The calculator truncated the answer. : On dividing 12 by 8, we get exactly 1.5. So, no truncation in the answer.
Therefore, correct option is B) The answer is exactly 1.5.
Has to be greater than 90 degrees.