The probability of an event being very likely means that it has a high chance of occurring, or the probability is close to 1. Remember that with probability, it goes from 0 to 1 only. There are no negatives, and it is all decimals.
Therefore, the correct answer is C. 0.89. This is because there is almost a 90% chance of the event occurring, as the probability is 0.89.
Hope this helps!! :)
