Concept:
The Integrated Management of Neonatal and Childhood Illness (IMNCI) provides standardized guidelines to assess and manage common childhood illnesses, including pneumonia. One of the key diagnostic indicators is the respiratory rate.
The threshold for "fast breathing" varies with age:
- < 2 months: $\geq$ 60 breaths/min
- 2 months -- 12 months: $\geq$ 50 breaths/min
- 12 months -- 5 years: $\geq$ 40 breaths/min
Step 1: Identify the age group.
The child falls in the 12 months to 5 years category.
Step 2: Recall the IMNCI threshold.
For this age group, fast breathing is defined as a respiratory rate of 40 or more breaths per minute.
Step 3: Select the correct option.
Thus, the correct threshold is $\geq$ 40 breaths per minute.