Final answer:
The burden of proof is on the government in instances where the IRS uses statistical data to recreate income and in cases of fraud with intent to evade tax. The relevant options indicating these scenarios are (a) and (b), thus the answer is 'only (a) and (b)'.
Step-by-step explanation:
Examples of instances where the burden of proof is on the government, rather than on the taxpayer, include when the IRS uses statistics to recreate income and in cases involving fraud with intent to evade tax. These scenarios align with the principles that, in the United States, taxpayers are generally presumed to have filed their taxes correctly, and it is the responsibility of the Internal Revenue Service (IRS) to prove otherwise should they challenge the filing.
Specifically, in cases where the IRS reconstructs income based on statistical data (a), the burden falls on the IRS to substantiate that reconstruction. Similarly, allegations of fraudulent activity with intent to evade tax (b) require the government to present sufficient evidence to prove the taxpayer's intent beyond a reasonable doubt. However, it should be noted that in cases involving corporations with a net worth exceeding $7 million (c), the burden of proof does not automatically shift to the government.
Therefore, the answer to the question is: only (a) and (b).