Final answer:
For AMT purposes, the statement that mining exploration and development costs must be capitalized and amortized over a specific period is true, but for AMT, the period might differ from the regular tax provisions.
Step-by-step explanation:
For Alternative Minimum Tax (AMT) purposes, the statement that mining exploration and development costs must be capitalized and amortized ratably over a 5-year period is True. According to IRS guidelines for AMT, taxpayers must capitalize certain costs associated with mining exploration and development and then amortize these costs over a specific period. In the case of mining property in the United States, these costs must indeed be amortized over a 10-year period for regular tax purposes, but for AMT purposes, the period is different. However, the specific period for AMT may vary based on the tax year and applicable tax laws at that time. Therefore, it is essential for taxpayers engaged in mining exploration or development to consult current tax regulations or a tax professional for up-to-date information.