Zygote of an organism developed after syngamy undergoes meiosis to form haploid spores, which divide mitotically and form the gametophyte. The organism must have ________ life cycle.

The correct option is A Haplontic
A. Haplontic: The main plant body is haploid. It produces gametes. No meiosis at the time of gamete formation. The male and female gametes to form zygospore(diploid). At the time of germination, the first division is meiosis result in the formation of haploid spores produce haploid plants. Such a life cycle is haplontic. E.g., Spirogyra.

B. Diplontic: The main plant body is Diploid. It produces gametes(Haploid). The male and female gametes to form Zygote(diploid). It produces a diploid plant body.

So, the correct answer is 'Haplontic'.