Answer:
A
Step-by-step explanation:
Each of the answers B, C, and D contain an aspect that will cause evolution to occur:
B. "Genetic variation"; this is basically the core essence of evolution. If there's genetic variation and it helps the organism survive better, then that species will gradually evolve to include that trait for better fitness.
C. "Competition"; with competition, it's like survival of the fittest: who can get the most prey and survive the longest. Without competition, organisms will simply get the food they want and will not be able to really evolve because none die.
D. "Predators capturing certain individuals"; this is kind of similar to C in that if an organism is caught by predators, it will lose its fitness and be less likely to survive. In order to avoid that, those organisms will want to evolve.
Only A doesn't cause evolution because it's a chance event that cannot be avoided.
Hope this helps!