A37-year-old insurance agent comes to the office with a report of trembling hands. she says that for the past 3 months when she tries to use her hands to fix her hair or cook they shake badly. she says she doesn't feel particularly nervous when this occurs, but she worries that other people will think she has an anxiety or alcohol disorder. she admits to having some recent fatigue, trouble with vision, and difficulty maintaining bladder control. her past medical history is remarkable for hypothyroidism. her mother has lupus and her father is healthy. she has an older brother with type 1 diabetes. she is married with three children. she denies tobacco, alcohol, or drug use. on examination, when she tries to reach for a pencil to fill out the health form, she has obvious tremours in her dominant hand. what type of tremour is most likely?