Answer:
B. Nutritionist
Step-by-step explanation:
Calories are a unit for the measurement of the amount of energy in different foods and drinks.
Pharmacists are responsible for the distribution of medication, which is not measured in calories so it is not A.
X-ray technician organise X-rays which scan the insides of people's bodies (most commonly bones) so they do not use calories.
Finally life technicians identify and collect loving organisms to study so they don't use calories either.
A nutritionist's is to evaluate the chemical make up of different foods i.e. How much energy hence calories, and how they work with different people's bodies, therefore B is correct.
Hope this helped!