Answer:
That statement is false.
Step-by-step explanation:
Typically, a slight increase in temperature wouldn't just outright kill the corals. However, that slight increase will most likely weaken them.
Corals rely on algaes that live inside their tissues as their source of nutrients and energy. When the corals is experiencing a sudden slight increase in temperature, this algae will be expelled from the tissue. This make the corals unable to obtain the same level of nutrients/energy compared and weaken them.