Alisa is directed by her neurologist to have a test that will measure the magnetic fields created by the electricity of the neurons in her brain. Which of the following tests will Alisa be most likely to have?

A) MRI
B) SQUID
C) fMRI
D) PET scan

Alisa is most likely to have a SQUID (Superconducting Quantum Interference Device) test which is used to measure the magnetic fields created by the electricity of the neurons in the brain. MRI (Magnetic Resonance Imaging) uses radio waves and a magnetic field to create images of the brain's structure, fMRI (Functional Magnetic Resonance Imaging) shows the brain's activity by measuring changes in blood flow, and PET (Positron Emission Tomography) scans involve injecting a radioactive tracer to measure metabolic activity in the brain. None of these tests specifically measure the magnetic fields created by neurons.