Step 1: Define "emulate."
"Emulate" signifies imitating or aiming to equal or surpass, typically in a positive or admiring way. It often describes copying someone to achieve similar success or quality.
Step 2: Examine the choices.
- "Echo" relates to sound repetition, not "emulate."
- "Reiterate" means to repeat speech, distinct from emulating.
- "Envy" is jealousy or desire for another's possessions, unrelated to emulating.
- "Mimic" means to imitate or copy, a direct synonym for "emulate."
Step 3: Determine the best fit. "Mimic" most closely matches "emulate" as both involve imitating actions or characteristics.Therefore, the correct option is 4. Mimic.
Final Answer: \[\boxed{\text{The correct answer is 4. Mimic}}\]