Final answer:
Insertions, deletions, and substitutions can cause fragment pattern differences in Restriction Fragment Length Polymorphism (RFLP).
Step-by-step explanation:
RFLP stands for Restriction Fragment Length Polymorphism, a DNA fingerprinting method that relies on the differences in DNA sequences among individuals. Variations in DNA sequences can be caused by different types of mutations including insertions, deletions, and substitutions. Therefore, all of the above options - insertions, deletions, and substitutions - can cause fragment pattern differences in RFLP.