Answer:
Option: dangling
Explanation:
Let's look at this sentence again:
They spotted a pod of killer whales driving along the ocean highway.
The subject of the sentence is whales.
Now, a modifier is considered dangling when the sentence does not make it clear about which subject is being modified. This happens when there is a misplaced modifier. A dangling modifier can be corrected by moving it to a different place like this:
While they were driving along the ocean highway, they spotted a pod of killer whales.
Now, the sentence is clear.
