Step 1: Understanding the one-word substitutes.
A laurel is a symbol of achievement and recognition, historically used to crown victors.
Step 2: Analyzing the options.
Option (A):
Incorrect. A mercenary refers to someone hired to fight for a foreign army, not a symbol of honor.
Option (B):
Incorrect. Carte blanche refers to complete freedom or authority, not an accolade.
Option (C):
Incorrect. Fiesta refers to a celebration or party, not an accolade.
Option (D):
Correct. "Laurel" is a symbol of honor and recognition, making it the correct choice.