A person is attempting to insert a key into a lock, but it is dark, and he cannot see the key or the lock. The key must be inserted with the correct side up ($2$ possibilities), and it must be inserted in the right orientation ($2$ possibilities) so that the teeth of the key align with the mechanism inside the lock. What is the probability of inserting the key correctly if he randomly selects an orientation for the key?

• A. $0.25$
• B. $0.50$
• C. $0.01$
• D. $0.10$

Answer: (A)