you can't (see)___him in her office last monday;he's been out of town for a month.空格应该如何填写?

you can't (see)___him in her office last monday;he's been out of town for a month.空格应该如何填写?
you can't (see)___him in her office last monday;he's been out of town for a month.
空格应该如何填写?

you can't (see)___him in her office last monday;he's been out of town for a month.空格应该如何填写?
have seen

couldn't have seen

have seen