Step 1: Definition of innate behavior.
- Innate behavior is genetically programmed and present at birth.
- It does not require prior experience or learning.
Step 2: Evaluate options.
- (A) Triggered by environment = can describe reflexes, but not fully correct.
- (B) Trained by parents = learned behavior.
- (C) Determined by heredity = correct definition of innate behavior.
- (D) Learned by hit and trial = learned behavior (operant conditioning).
Therefore, innate behavior is a behavior determined by heredity.