I am doing my dad's taxes and I'm stuck on a form 2210 line d withholding document. I've never seen this before and don't know what to do. How do I fix this?

Option D says your withholding was not evenly taken out over the year, as assumed by the default calculation, this may or may not reduce your penalty

@greghelengary 

Form 2210 is used to see if you owe a penalty for underpaying your estimated tax. Part II, D is checked if you want you want to figure your penalty based on the dates of your withholding.

For more information, refer to the TurboTax articles How do I add Form 2210?, Form 2210 Instructions: How to Calculate and Pay Estimated Taxes to Avoid Penalties and What is Form 2210?

@greghelengary