Advancements in nuclear science have led to new technology which have been beneficial to society. many of the advances are used in medicine. which is not a medical use of nuclear energy? a) nuclear fusion b) radioimmunotherapy c) magnetic resonance imaging (mri) d) positron emission tomography (pet)

Option A, nuclear fusion

Explanation:

Nuclear fusion is the base reaction that is being carried out to produce nuclear energy along with nuclear fission reaction. Thus, the term "nuclear fusion" do not depict any form of application of nuclear energy.

However, the radioimmunotherapy, magnetic resonance imaging (MRI) and positron emission tomography (PET) uses nuclear energy as a better and advanced diagnostic and therapy  tool . Therefore, these three can be considered as application of nuclear energy.

Hence, option A is the correct answer.