Which of the following is/are example(s) of Quasi-Experimental designs?

Quasi-experimental designs lack random assignment, and the Non-Equivalent Control Group design along with both Interrupted Time-Series designs fits this criterion.

The Non-Equivalent Control Group design compares intact groups without randomisation.

The Single-Group Interrupted Time-Series design tracks one group across repeated measures before and after an intervention.

The Control-Group Interrupted Time-Series design adds a comparison series to strengthen inference.

The Posttest-Only Control Group design and the Solomon Four-Group design use random assignment, making them true experiments.

Absence of randomisation is the defining line between quasi-experimental and true experimental designs.