Final answer:
The appropriate attack that causes a collision using the same hash function is the Birthday attack, which exploits the birthday paradox.
Step-by-step explanation:
The appropriate attack that sends two different messages using the same hash function, therefore causing a collision is the Birthday attack. In a Birthday attack, the attacker attempts to find two different inputs that produce the same hash output, exploiting the birthday paradox.
The birthday paradox states that in a group of just 23 people, there is a 50% chance that two people share the same birthday. Similarly, in hash functions with a fixed output size, there is a higher probability of finding two inputs that hash to the same value, even though there are more possible inputs.