The emergency nurse is triaging four clients. Which client should the nurse assess first?
选项：

A:

6-month-old client who is constipated, cannot hold the head up, and has a weak cry after eating honey

B:

4-year-old client who has elbow pain, swelling, and deformity after falling from a playground swing

C:

6-year-old client who has fever and reports right-sided abdominal pain and difficulty tolerating food

D:

9-year-old client who is lethargic and reports having painful urination and back pain