Which of the following options is not a bryophyte?

Reason: Bryophyte represents a unique group of plants intermediate between the predominantly aquatic thallophytes and terrestrial pteridophytes. They inhabit a zone, which is neither completely land nor completely water. Thus, bryophytes are often regarded as amphibians of plant kingdom. Like amphibians, bryophytes can survive on land and require water for fertilization. Mostly, the plant body of bryophytes is differentiated to form stem and leaf like structures. However, there is no specialized tissue for the conduction of water and other substances from one part of the plant body to another. Examples are moss and marchantia. 

Marsilea - is an aquatic fern. As it is a fern, it belongs to pteridophyta.