In plants, which of the following are produced by meiosis?

a. haploid gametes

b. diploid gametes

c. haploid spores

d. diploid spores

The correct answer is option c. Haploid spores.

Explanation:

In the plants, spores are normally unicellular and haploid and produced by the process of meiosis in the sporophytic body of the plant.

These haploid spores undergo the mitotic division and develop a new individual called gametophyte that forms gametes eventually.

Thus, the correct answer is option C. Haploid spores.