Step 1: Understanding catalytic oxidation of ammonia.
The catalytic oxidation of ammonia at high temperatures produces nitrogen monoxide (NO) as the main product. This reaction is important in the production of nitric acid.
Step 2: Analyzing the options.
(A) N\(_2\)O: This is not the main product of ammonia oxidation.
(B) NO: Correct — Nitrogen monoxide (NO) is the main product of catalytic oxidation of ammonia.
(C) HNO\(_2\): This is not the product of catalytic oxidation, but rather formed in other processes.
(D) NO\(_2\): NO\(_2\) is not the direct product of the catalytic oxidation of ammonia.
Step 3: Conclusion.
The correct answer is (B) NO.