I believe the correct answer is in contrast to Greek temples, Roman temples usually had columns attached to the walls completely or partly which makes a pseudo-peripteral structure.
Roman temples had a pseudo-peripteral structure rather than peripteral structure that Greek temples had. The temple of pseudo-peripteral structure has free standing columns in the front, but the columns along the sides are engaged (attached partly or completely to the wall) in the peripheral walls of the naos. For example, the Temple of Athena Nike and Temple of Venus and Roma have this kind of structure.
