My aunt has invited me to her place _____ three o’clock this afternoon _____ tea.

My aunt has invited me to her place _ three o’clock this afternoon _ tea.

At, for

On, to

During, so that

From, for

We use preposition at before clock. Like at 7 o' clock, at 9 o'clock, at 4 o' clock.

We use preposition for to tell a reason. (Here tea is the reason of invitation)

My aunt has invited me to her place at three o’clock this afternoon for tea.