Which organism has a haploid plant body?

Read the given statements and choose the correct option:
Statement $I$: Gemmae are green unicellular sexual buds which develop in receptacles called gemma cups.
Statement $II$: Protonema develops directly from a spore.

Identify the mosses and liverworts from the following list:
$I$ - $Sphagnum$,$II$ - $Funaria$,
$III$ - $Marchantia$,$IV$ - $Polytrichum$
$\text{Mosses} \quad\quad \text{Liverworts}$

Give the economic importance of bryophytic plants.

In bryophytes,the sporophyte stage is responsible for which of the following?

The protonema stage develops from $........$,and the leafy stage develops from $........$.