Step 1: Understanding the Concept
BHT is butylated hydroxytoluene, used in foods and oils to prevent spoilage by oxygen.
Step 2: Function
It reacts with free radicals formed during oxidation of fats, so it acts as an antioxidant. BHA is used similarly.
Step 3: Compare the options
The use of BHT is as an antioxidant, option (A).
Final Answer:
BHT is used as an antioxidant.
\[ \boxed{\text{(A) }\text{As antioxidant}} \]