Science Cannot Yet Describe "Thinking" in Physical Terms

Multiple Choice

Science cannot yet describe "thinking" in physical terms.However,we know that it involves metabolism within brain cells.With positron emission tomography (PET) scan or activity nuclear magnetic resonance (NMR) it is possible to image the regions of the brain that are most metabolically active during various mental activities.For different mental functions,different regions and nerve cells become active.However,

A) the cellular energy expended in "thinking" must be less than the chemical bond energy supplied in food to these brain cells.
B) "thought" cannot be linked to cell processes because energy is not related to matter.
C) since thoughts can repeat,the requirement for a continual input of energy to prevent entropy does not apply to this cell activity.
D) "thinking" is beyond the scope of science to study.