Union Government tax with the highest annual yield: Choose the historically largest revenue head. Context: Treat the question in the pre-GST framework commonly used in legacy GK (Union excise, customs, income tax, corporation tax). Choose the tax that has historically yielded the highest annual revenue under that framework.

Given data

• Question asks for the Union tax head with the highest annual yield in the traditional, pre-GST classification.

Concept / Approach
Before GST consolidation, Union excise duties on manufactured goods were a dominant and stable source of the Union Government's tax revenue, typically exceeding customs revenue and often rivaling or surpassing personal income tax.

Option analysis
Union excise duties: Historically the largest single Union tax head in many years pre-GST. Customs duties: Significant but generally below excise during many years. Personal income tax: Important direct tax head but typically lower than excise in the older framework. Agricultural income tax: Levied by states, not a Union tax head.

Common pitfalls
Mixing up post-2017 GST collections with the legacy classification the question refers to.

Final Answer
Union excise duties (pre-GST era).