Which of the following statements is correct with respect to bryophyte development?
haploid gametes mate to produce a diploid zygote, which later develops into a protonema.
the diploid zygote germinates to give rise to protonema, which later develops into a sporophyte.
haploid spores germinate to give rise to protonema, which later develops into a sporophyte.

The answer is Haploid spores germinate to give rise to protonema, which later develops into a sporophyte.

A protonema (plural: protonemata) is a thread-like chain of cells that forms the earliest stage (the haploid phase) of a bryophyte life cycle..
A haploid gametophyte ( each of whose cells contains a fixed number of unpaired chromosomes)  gives rise to a diploid sporophyte,. Gametophytes produce haploid sperm and eggs which fuse to form diploid zygotes that grow into sporophytes.