That depends on the income that is on your tax return.
Line 2a lists tax exempt interest. If you have some tax exempt interest, it should show there.
Line 4a is IRA distributions. If you have an IRA distribution, and part of it is not taxed, the full amount shows on 4a and the taxable part shows on 4b.
Line 4c shows total pension and annuities. If you have pensions and annuities and part of it is not taxed, the full amount shows on 4c and the taxable part shows on 4d.
When your retirement distributions are fully taxable, the amount shows on 4b or 4d only. Here are two excerpts from the IRS instructions for Form 1040, explaining how to complete these lines:
If your pension or annuity is fully taxable, enter the total pension or annuity payments (from Form(s) 1099-R, box 1) on line 4d; don’t make an entry on line 4c.
Except as provided next, leave line 4a blank and enter the total distribution (from Form
1099-R, box 1) on line 4b.