For the Past Year, 30-Year-Old Kendra Has Experienced Difficulty Falling

Multiple Choice

For the past year, 30-year-old Kendra has experienced difficulty falling and staying asleep, and she frequently complains that she has difficulty remembering certain things, such as where she put her keys or an upcoming dentist or doctor's appointment. Kendra says she's stressed and was recently diagnosed with depression. Kendra probably has a deficiency in the neurotransmitter:

A) pectin.
B) norepinephrine.
C) pepsin.
D) glutamate.