Final answer:
The word 'emerging' is the correct replacement for 'nascent' in the passage, as it closely reflects the idea of a philosophy that is just beginning to develop.
Step-by-step explanation:
The word nascent in the passage describes something that is in the early stages of development, essentially a budding or emerging belief system. Among the answer choices given, 'emerging' would most closely replace nascent without changing the meaning of the passage. 'Emerging' signifies something that is just beginning to come into existence or starting to be noticeable, which aligns with the context of the passage where the student's moral philosophy is just beginning to form and crystallize.
It is important to note that the other options 'unfounded,' 'fictional,' and 'deeply-held' do not convey the same meaning as 'nascent.' 'Unfounded' would imply that the philosophy lacks basis, which is not suggested by the context. 'Fictional' would suggest the philosophy is not real, which would also change the meaning. 'Deeply-held' implies an established, strongly felt belief, which is contrary to the idea of something being nascent and therefore would significantly alter the passage's meaning.
In the larger context of growth and development of personal philosophy, reaching an understanding of beliefs and the realization that some may contradict others is a part of intellectual growth, bringing one from comfort and familiarity into new realms of thought that are aligned with the idea of something being nascent.