Answer:
3. A sauce made thicker by boiling.
Step-by-step explanation:
fra·grant
adjective
having a pleasant or sweet smell.
"she gathered the fragrant blooms"
Reduction is performed by simmering or boiling a liquid such as stock, fruit or vegetable juices, wine, vinegar, or a sauce until the desired concentration is reached by evaporation. This is done without a lid, enabling the vapor to escape from the mixture.
Most food has a fragrance.
So, a fragrant reduction is to simmer or boil something to make it thicker.