As you can see in the images, there are 3 types of natural selection:
- Disruptive: In which the phenotypes at the extremes prevail instead of the phenotype in the middle which is the average.
- Stabilization: In which the middle phenotype prevails.
- Directional: One of the extreme phenotypes prevails.
Speciation is a process in which new species are formed from an initial species and can occur due to various conditions and therefore, there are several types. An example is the image (allopatric speciation) in which a geographic barrier divides the individuals of the population and over time, these give rise to different species.
Since disruptive selection is the only one that favors the presence of more than one phenotype, it is more likely to produce a speciation phenomenon in which 2 or more distinct species are obtained over time. Therefore, the answer is A.
