What could happen if you grab at the front brake too hard?

Answer: C — Cause wheel lock

If you grab at the front brake too hard while riding a motorcycle, it could cause the front wheel to lock up. When the front wheel locks, the motorcycle loses traction and stability, potentially leading to a loss of control and a dangerous situation such as a skid or a fall. Therefore, it is crucial to be gentle and progressive when applying the front brake to avoid causing a wheel lock. This is why option C, "Cause wheel lock," is the correct answer.