Which statement about a 401(k) is true?

A 401(k) account cannot help you save for retirement.
Money put into a 401(k) is pre-tax, lowering your overall tax paid.
Using money in a 401(k) for an emergency should be your first choice.
Having a 401(k) is mandatory.

Money put into a 401(k) is pre-tax, lowering your overall tax paid.

The statement that is true about a 401(k) is that money put into a 401(k) is pre-tax, lowering your overall tax paid.