Final answer:
The interval in which 1/b^2 lies is Interval IV.
Step-by-step explanation:
The expression 1/b^2 represents a quadratic function. To determine the interval in which this function lies, we need to evaluate its sign for different values of b.
If b < 0, then b^2 > 0 and 1/b^2 > 0. Therefore, the function is positive in Interval II.
If b = 0, then 1/b^2 is undefined.
If b > 0, then b^2 > 0 and 1/b^2 > 0. Therefore, the function is positive in Interval IV.
Based on the analysis above, the interval in which 1/b^2 is positive is Interval II and Interval IV. Therefore, the answer is Option D: Interval IV.