Answer :
Photosynthetic organisms can be found in ocean regions with sufficient sunlight, such as the photic zone, intertidal zone, neritic zone, and the sunlit upper layers of the oceanic zone. Places lacking light, like the aphotic and abyssal zones, or the deep benthic realm, do not support photosynthetic life. Therefore the correct answer is a.
The term used to describe the lower portion of the photic zone is not the benthic zone, aphotic zone, transition zone, nor the abyssal zone. However, I would like to clarify the concept related to photosynthetic organisms' presence in different oceanic regions. Photosynthetic organisms, which require sunlight to produce energy, are predominantly found in the photic zone, where there is enough light penetration to support photosynthesis. The intertidal zone, being at the edge of land and sea, also receives sunlight and supports these organisms. The neritic zone refers to the coastal waters where sunlight reaches the ocean bottom and supports the vibrant marine life, including photosynthetic organisms. The oceanic zone includes waters beyond the neritic zone and can support photosynthesis only in its upper layers, which are sunlit.
Regarding deep-sea zones, the aphotic zone lacks sufficient light for photosynthesis, hence photosynthetic organisms are absent there. Similarly, the abyssal zone, which is a deep-sea layer, and the benthic realm, which can include deep ocean floors, are not sites for photosynthetic life due to the absence of light. Thus, the correct answer to the question "In which of the following regions would you expect to find photosynthetic organisms?" is the photic zone, the intertidal zone, the neritic zone, and the oceanic zone.
