Answer:
The rule that most closely applies to the word "predict" is:
Group I. If the root is a full word, the ending is usually -able.
Step-by-step explanation:
"Predict" has "dict" as its root, which is a full word, and we know that the correct spelling for its derived form is "predictable". We can, thus, eliminate the last two options. "Predict" does not end in -e, -g, -c, or -a. This is already its complete form. With that in mind, we can easily see that the group I rule is the one that best applies to it. The suffix -able is usually applied to roots that are a full word, which is the case with "predict".