Final answer:
Species found at Olduvai Gorge include Paranthropus boisei, Homo habilis, and Homo erectus, indicating 'e) all of the above' as the correct answer to the student's question.
Step-by-step explanation:
The question refers to the hominin fossils discovered at Olduvai Gorge, which is a significant archaeological site in Tanzania. In the context of this location, the species found include Paranthropus boisei, Homo habilis, and Homo erectus. Notably, Paranthropus boisei was discovered by Mary and Louis Leakey in 1959 and is noted for its robust skull features, including a prominent sagittal crest. Homo habilis, one of the earliest members of the genus Homo, was also found here and is known for being potentially one of the first hominins to use tools. Lastly, Homo erectus is another species that has been found in Olduvai Gorge and is an important part of human evolution. Consequently, the correct answer to the student's question is 'e) all of the above'.