The correct option is C Long, curved and biflagellate
An antheridium (plural: antherida) is a haploid structure or organ producing and containing male gametes (called antherozoids or sperm). In general, the male gametes (antherozoids) are produced in globose structures (antheridia), that are either stalked or sunken in the gametophyte. The antherozoids of Marchantia are long, curved, and biflagellate.